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rfc:rfc6313

Internet Engineering Task Force (IETF) B. Claise Request for Comments: 6313 G. Dhandapani Updates: 5102 P. Aitken Category: Standards Track S. Yates ISSN: 2070-1721 Cisco Systems, Inc.

                                                             July 2011
  Export of Structured Data in IP Flow Information Export (IPFIX)

Abstract

 This document specifies an extension to the IP Flow Information
 Export (IPFIX) protocol specification in RFC 5101 and the IPFIX
 information model specified in RFC 5102 to support hierarchical
 structured data and lists (sequences) of Information Elements in data
 records.  This extension allows definition of complex data structures
 such as variable-length lists and specification of hierarchical
 containment relationships between Templates.  Finally, the semantics
 are provided in order to express the relationship among multiple list
 elements in a structured data record.

Status of This Memo

 This is an Internet Standards Track document.
 This document is a product of the Internet Engineering Task Force
 (IETF).  It represents the consensus of the IETF community.  It has
 received public review and has been approved for publication by the
 Internet Engineering Steering Group (IESG).  Further information on
 Internet Standards is available in Section 2 of RFC 5741.
 Information about the current status of this document, any errata,
 and how to provide feedback on it may be obtained at
 http://www.rfc-editor.org/info/rfc6313.

Copyright Notice

 Copyright (c) 2011 IETF Trust and the persons identified as the
 document authors.  All rights reserved.
 This document is subject to BCP 78 and the IETF Trust's Legal
 Provisions Relating to IETF Documents
 (http://trustee.ietf.org/license-info) in effect on the date of
 publication of this document.  Please review these documents
 carefully, as they describe your rights and restrictions with respect
 to this document.  Code Components extracted from this document must
 include Simplified BSD License text as described in Section 4.e of

Claise, et al. Standards Track [Page 1] RFC 6313 Export of Structured Data in IPFIX July 2011

 the Trust Legal Provisions and are provided without warranty as
 described in the Simplified BSD License.

Table of Contents

 1. Overview ........................................................5
    1.1. IPFIX Documents Overview ...................................5
    1.2. Relationship between IPFIX and PSAMP .......................6
 2. Introduction ....................................................6
    2.1. The IPFIX Track ............................................7
    2.2. The IPFIX Limitations ......................................8
    2.3. Structured Data Use Cases ..................................8
    2.4. Specifications Summary ....................................11
 3. Terminology ....................................................11
    3.1. New Terminology ...........................................12
    3.2. Conventions Used in This Document .........................12
 4. Linkage with the IPFIX Information Model .......................12
    4.1. New Abstract Data Types ...................................12
         4.1.1. basicList ..........................................12
         4.1.2. subTemplateList ....................................12
         4.1.3. subTemplateMultiList ...............................12
    4.2. New Data Type Semantic ....................................13
         4.2.1. List ...............................................13
    4.3. New Information Elements ..................................13
         4.3.1. basicList ..........................................13
         4.3.2. subTemplateList ....................................13
         4.3.3. subTemplateMultiList ...............................13
    4.4. New Structured Data Type Semantics ........................13
         4.4.1. undefined ..........................................14
         4.4.2. noneOf .............................................14
         4.4.3. exactlyOneOf .......................................14
         4.4.4. oneOrMoreOf ........................................15
         4.4.5. allOf ..............................................16
         4.4.6. ordered ............................................16
    4.5. Encoding of IPFIX Data Types ..............................16
         4.5.1. basicList ..........................................17
         4.5.2. subTemplateList ....................................19
         4.5.3. subTemplateMultiList ...............................21
 5. Structured Data Format .........................................25
    5.1. Length Encoding Considerations ............................25
    5.2. Recursive Structured Data .................................26
    5.3. Structured Data Information Elements Applicability
         in Options Template Sets ..................................26
    5.4. Usage Guidelines for Equivalent Data Representations ......27
    5.5. Padding ...................................................29
    5.6. Semantic ..................................................29
 6. Template Management ............................................33
 7. The Collecting Process's Side ..................................33

Claise, et al. Standards Track [Page 2] RFC 6313 Export of Structured Data in IPFIX July 2011

 8. Defining New Information Elements Based on the New
    Abstract Data Types ............................................34
 9. Structured Data Encoding Examples ..............................34
    9.1. Encoding a Multicast Data Record with basicList ...........35
    9.2. Encoding a Load-Balanced Data Record with a basicList .....37
    9.3. Encoding subTemplateList ..................................38
    9.4. Encoding subTemplateMultiList .............................41
    9.5. Encoding an Options Template Set Using Structured Data ....46
 10. Relationship with the Other IPFIX Documents ...................51
    10.1. Relationship with Reducing Redundancy ....................51
         10.1.1. Encoding Structured Data Element Using
                 Common Properties .................................51
         10.1.2. Encoding Common Properties Elements with
                 Structured Data Information Element ...............51
    10.2. Relationship with Guidelines for IPFIX Testing ...........53
    10.3. Relationship with IPFIX Mediation Function ...............54
 11. IANA Considerations ...........................................54
    11.1. New Abstract Data Types ..................................54
         11.1.1. basicList .........................................54
         11.1.2. subTemplateList ...................................54
         11.1.3. subTemplateMultiList ..............................55
    11.2. New Data Type Semantics ..................................55
         11.2.1. list ..............................................55
    11.3. New Information Elements .................................55
         11.3.1. basicList .........................................55
         11.3.2. subTemplateList ...................................56
         11.3.3. subTemplateMultiList ..............................56
    11.4. New Structured Data Semantics ............................56
         11.4.1. undefined .........................................56
         11.4.2. noneOf ............................................57
         11.4.3. exactlyOneOf ......................................57
         11.4.4. oneOrMoreOf .......................................57
         11.4.5. allOf .............................................57
         11.4.6. ordered ...........................................58
 12. Security Considerations .......................................58
 13. References ....................................................58
    13.1. Normative References .....................................58
    13.2. Informative References ...................................58
 14. Acknowledgements ..............................................59
 Appendix A. Additions to XML Specification of IPFIX
             Information Elements and Abstract Data Types ..........60
 Appendix B. Encoding IPS Alert Using Structured Data
             Information Elements ..................................65

Claise, et al. Standards Track [Page 3] RFC 6313 Export of Structured Data in IPFIX July 2011

Table of Figures

Figure 1:  basicList Encoding ......................................17
Figure 2:  basicList Encoding with Enterprise Number ...............18
Figure 3:  Variable-Length basicList Encoding (Length < 255 Octets) 18
Figure 4:  Variable-Length basicList Encoding (Length 0 to 65535
           Octets) .................................................19
Figure 5:  subTemplateList Encoding ................................19
Figure 6:  Variable-Length subTemplateList Encoding
           (Length < 255 Octets) ...................................20
Figure 7:  Variable-Length subTemplateList Encoding
           (Length 0 to 65535 Octets) ..............................21
Figure 8:  subTemplateMultiList Encoding ...........................21
Figure 9:  Variable-Length subTemplateMultiList Encoding
           (Length < 255 Octets) ...................................23
Figure 10: Variable-Length subTemplateMultiList Encoding
           (Length 0 to 65535 Octets) ..............................24
Figure 11: Encoding basicList, Template Record .....................35
Figure 12: Encoding basicList, Data Record, Semantic allOf .........36
Figure 13: Encoding basicList, Data Record with Variable-Length
           Elements, Semantic allOf ................................37
Figure 14: Encoding basicList, Data Record, Semantic exactlyOneOf ..38
Figure 15: Encoding subTemplateList, Template for One-Way Delay
           Metrics .................................................39
Figure 16: Encoding subTemplateList, Template Record ...............40
Figure 17: Encoding subTemplateList, Data Set ......................40
Figure 18: Encoding subTemplateMultiList, Template for Filtering
           Attributes ..............................................44
Figure 19: Encoding subTemplateMultiList, Template for Sampling
           Attributes ..............................................44
Figure 20: Encoding subTemplateMultiList, Template for Flow Record .45
Figure 21: Encoding subTemplateMultiList, Data Set .................45
Figure 22: PSAMP SSRI to Be encoded ................................48
Figure 23: Options Template Record for PSAMP SSRI Using
           subTemplateMultiList ....................................48
Figure 24: PSAMP SSRI, Template Record for interface ...............49
Figure 25: PSAMP SSRI, Template Record for linecard ................49
Figure 26: PSAMP SSRI, Template Record for linecard and interface ..49
Figure 27: Example of a PSAMP SSRI Data Record, Encoded Using a
           subTemplateMultiList ...................................50
Figure 28: Common and Specific Properties Exported Together
           [RFC5473] ..............................................51
Figure 29: Common and Specific Properties Exported Separately
           According to [RFC5473] .................................52
Figure 30: Common and Specific Properties Exported with Structured
           Data Information Element ...............................52
Figure 31: Encoding IPS Alert, Template for Target ................67
Figure 32: Encoding IPS Alert, Template for Attacker ..............68

Claise, et al. Standards Track [Page 4] RFC 6313 Export of Structured Data in IPFIX July 2011

Figure 33: Encoding IPS Alert, Template for Participant ...........68
Figure 34: Encoding IPS Alert, Template for IPS Alert .............69
Figure 35: Encoding IPS Alert, Data Set ...........................69

1. Overview

1.1. IPFIX Documents Overview

 The IPFIX protocol [RFC5101] provides network administrators with
 access to IP Flow information.
 The architecture for the export of measured IP Flow information out
 of an IPFIX Exporting Process to a Collecting Process is defined in
 the IPFIX architecture [RFC5470], per the requirements defined in RFC
 3917 [RFC3917].
 The IPFIX architecture [RFC5470] specifies how IPFIX Data Records and
 Templates are carried via a congestion-aware transport protocol from
 IPFIX Exporting Processes to IPFIX Collecting Processes.
 IPFIX has a formal description of IPFIX Information Elements, their
 name, type, and additional semantic information, as specified in the
 IPFIX information model [RFC5102].
 In order to gain a level of confidence in the IPFIX implementation,
 probe the conformity and robustness, and allow interoperability, the
 guidelines for IPFIX testing [RFC5471] present a list of tests for
 implementers of compliant Exporting Processes and Collecting
 Processes.
 The Bidirectional Flow Export [RFC5103] specifies a method for
 exporting bidirectional flow (biflow) information using the IP Flow
 Information Export (IPFIX) protocol, representing each biflow using a
 single Flow Record.
 "Reducing Redundancy in IP Flow Information Export (IPFIX) and Packet
 Sampling (PSAMP) Reports" [RFC5473] specifies a bandwidth-saving
 method for exporting Flow or packet information, by separating
 information common to several Flow Records from information specific
 to an individual Flow Record: common Flow information is exported
 only once.

Claise, et al. Standards Track [Page 5] RFC 6313 Export of Structured Data in IPFIX July 2011

1.2. Relationship between IPFIX and PSAMP

 The specification in this document applies to the IPFIX protocol
 specifications [RFC5101].  All specifications from [RFC5101] apply
 unless specified otherwise in this document.
 The Packet Sampling (PSAMP) protocol [RFC5476] specifies the export
 of packet information from a PSAMP Exporting Process to a PSAMP
 Collecting Process.  Like IPFIX, PSAMP has a formal description of
 its information elements, their name, type, and additional semantic
 information.  The PSAMP information model is defined in [RFC5477].
 As the PSAMP protocol specifications [RFC5476] are based on the IPFIX
 protocol specifications, the specifications in this document are also
 valid for the PSAMP protocol.
 Indeed, the major difference between IPFIX and PSAMP is that the
 IPFIX protocol exports Flow Records while the PSAMP protocol exports
 Packet Reports.  From a pure export point of view, IPFIX will not
 distinguish a Flow Record composed of several packets aggregated
 together from a Flow Record composed of a single packet.  So the
 PSAMP export can be seen as a special IPFIX Flow Record containing
 information about a single packet.

2. Introduction

 While collecting the interface counters every five minutes has proven
 to be useful in the past, more and more granular information is
 required from network elements for a series of applications:
 performance assurance, capacity planning, security, billing, or
 simply monitoring.  However, the amount of information has become so
 large that, when dealing with highly granular information such as
 Flow information, a push mechanism (as opposed to a pull mechanism,
 such as Simple Network Management Protocol (SNMP)) is the only
 solution for routers whose primary function is to route packets.
 Indeed, polling short-lived Flows via SNMP is not an option: high-end
 routers can support hundreds of thousands of Flows simultaneously.
 Furthermore, in order to reduce the export bandwidth requirements,
 the network elements have to integrate mediation functions to
 aggregate the collected information, both in space (typically, from
 different linecards or different Exporters) and in time.
 Typically, it would be beneficial if access routers could export Flow
 Records, composed of the counters before and after an optimization
 mechanism on the egress interface, instead of exporting two Flow
 Records with identical tuple information.

Claise, et al. Standards Track [Page 6] RFC 6313 Export of Structured Data in IPFIX July 2011

 In terms of aggregation in time, let us imagine that, for performance
 assurance, the network management application must receive the
 performance metrics associated with a specific Flow, every
 millisecond.  Since the performance metrics will be constantly
 changing, there is a new dimension to the Flow definition: we are not
 dealing anymore with a single Flow lasting a few seconds or a few
 minutes, but with a multitude of one millisecond sub-flows for which
 the performance metrics are reported.
 Which current protocol is suitable for these requirements: push
 mechanism, highly granular information, and huge number of similar
 records? IPFIX, as specified in RFC 5101 would give part of the
 solution.

2.1. The IPFIX Track

 The IPFIX working group has specified a protocol to export Flow
 information [RFC5101].  This protocol is designed to export
 information about IP traffic Flows and related measurement data,
 where a Flow is defined by a set of key attributes (e.g., source and
 destination IP address, source and destination port).
 The IPFIX protocol specification [RFC5101] specifies that traffic
 measurements for Flows are exported using a TLV (type, length, value)
 format.  The information is exported using a Template Record that is
 sent once to export the {type, length} pairs that define the data
 format for the Information Elements in a Flow.  The Data Records
 specify values for each Flow.
 Based on the requirements for IP Flow Information Export (IPFIX)
 [RFC3917], the IPFIX protocol has been optimized to export Flow-
 related information.  However, thanks to its Template mechanism, the
 IPFIX protocol can export any type of information, as long as the
 relevant Information Element is specified in the IPFIX information
 model [RFC5102], registered with IANA [IANA-IPFIX], or specified as
 an enterprise-specific Information Element.  For each Information
 Element, the IPFIX information model [RFC5102] defines a numeric
 identifier, an abstract data type, an encoding mechanism for the data
 type, and any semantic constraints.  Only basic, single-valued data
 types, e.g., numbers, strings, and network addresses, are currently
 supported.

Claise, et al. Standards Track [Page 7] RFC 6313 Export of Structured Data in IPFIX July 2011

2.2. The IPFIX Limitations

 The IPFIX protocol specification [RFC5101] does not support the
 encoding of hierarchical structured data and arbitrary-length lists
 (sequences) of Information Elements as fields within a Template
 Record.  As it is currently specified, a Data Record is a "flat" list
 of single-valued attributes.  However, it is a common data modeling
 requirement to compose complex hierarchies of data types, with
 multiple occurrences, e.g., 0..* cardinality allowed for instances of
 each Information Element in the hierarchy.
 A typical example is the MPLS label stack entries model.  An early
 NetFlow implementation used two Information Elements to represent the
 MPLS label stack entry: a "label stack entry position" followed by a
 "label stack value".  However, several drawbacks were discovered.
 Firstly, the Information Elements in the Template Record had to be
 imposed so that the position would always precede the value.
 However, some encoding optimizations are based on the permutation of
 Information Element order.  Secondly, a new semantic intelligence,
 not described in the information model, had to be hard-coded in the
 Collecting Process: the label value at the position "X" in the stack
 is contained in the "label stack value" Information Element following
 by a "label stack entry position" Information Element containing the
 value "X".  Therefore, this model was abandoned.
 The selected solution in the IPFIX information model [RFC5102] is a
 long series of Information Elements: mplsTopLabelStackSection,
 mplsLabelStackSection2, mplsLabelStackSection3,
 mplsLabelStackSection4, mplsLabelStackSection5,
 mplsLabelStackSection6, mplsLabelStackSection7,
 mplsLabelStackSection8, mplsLabelStackSection9,
 mplsLabelStackSection10.  While this model removes any ambiguity, it
 overloads the IPFIX information model with repetitive information.
 Furthermore, if mplsLabelStackSection11 is required, IANA
 [IANA-IPFIX] will not be able to assign the new Information Element
 next to the other ones in the registry, which might cause some
 confusion.

2.3. Structured Data Use Cases

 Clearly, the MPLS label stack entries issue can best be solved by
 using a real structured data type composed of ("label stack entry
 position", "label stack value") pairs, potentially repeated multiple
 times in Flow Records, since this would be the most efficient from an
 information model point of view.

Claise, et al. Standards Track [Page 8] RFC 6313 Export of Structured Data in IPFIX July 2011

 Some more examples enter the same category: how to encode the list of
 output interfaces in a multicast Flow, how to encode the list of BGP
 Autonomous Systems (AS) in a BGP Flow, how to encode the BGP
 communities in a BGP Flow, etc.
 The one-way delay passive measurement, which is described in the
 IPFIX applicability [RFC5472], is yet another example that would
 benefit from a structured data encoding.  Assuming synchronized
 clocks, the Collector can deduce the one-way delay between two
 Observation Points from the following two Information Elements,
 collected from two different Observation Points:
  1. Packet arrival time: observationTimeMicroseconds [RFC5477]
  2. Packet ID: digestHashValue [RFC5477]
 In practice, this implies that many pairs of
 (observationTimeMicroseconds, digestHashValue) must be exported for
 each Observation Point, even if Hash-Based Filtering [RFC5475] is
 used.  On top of that information, if the requirement is to
 understand the one-way delay per application type, the 5-tuple
 (source IP address, destination IP address, protocol, source port,
 destination port) would need to be added to every Flow Record.
 Instead of exporting this repetitive 5-tuple, as part of every single
 Flow Record a Flow Record composed of a structured data type such as
 the following would save a lot of bandwidth:
    5-tuple
              { observationTimeMicroseconds 1, digestHashValue 1 }
              { observationTimeMicroseconds 2, digestHashValue 2 }
              { observationTimeMicroseconds 3, digestHashValue 3 }
              { ...  , ... }

Claise, et al. Standards Track [Page 9] RFC 6313 Export of Structured Data in IPFIX July 2011

 As a last example, here is a more complex case of hierarchical
 structured data encoding.  Consider the example scenario of an IPS
 (Intrusion Prevention System) alert data structure containing
 multiple participants, where each participant contains multiple
 attackers and multiple targets, with each target potentially composed
 of multiple applications, as depicted below:
    alert
        signatureId
        protocolIdentifier
        riskRating
        participant 1
            attacker 1
                sourceIPv4Address
                applicationId
            ...
            attacker N
                sourceIPv4Address
                applicationId
            target 1
                destinationIPv4Address
                applicationId 1
                ...
                applicationId n
            ...
            target N
                destinationIPv4Address
                applicationId 1
                ...
                applicationId n
        participant 2
            ...
 To export this information in IPFIX, the data would need to be
 flattened (thus, losing the hierarchical relationships) and a new
 IPFIX Template created for each alert, according to the number of
 applicationId elements in each target, the number of targets and
 attackers in each participant, and the number of participants in each
 alert.  Clearly, each Template will be unique to each alert, and a
 large amount of CPU, memory, and export bandwidth will be wasted
 creating, exporting, maintaining, and withdrawing the Templates.  See
 Appendix B for a specific example related to this case study.

Claise, et al. Standards Track [Page 10] RFC 6313 Export of Structured Data in IPFIX July 2011

2.4. Specifications Summary

 This document specifies an IPFIX extension to support hierarchical
 structured data and variable-length lists by defining three new
 Information Elements and three corresponding new abstract data types
 called basicList, subTemplateList, and subTemplateMultiList.  These
 are defined in Sections 4.1 and 4.3.
 The three Structured Data Information Elements carry some semantic
 information so that the Collecting Process can understand the
 relationship between the different list elements.  The semantic in
 the Structured Data Information Elements is provided in order to
 express the relationship among the multiple top-level list elements.
 As an example, if a list is composed of the elements (A,B,C), the
 semantic expresses the relationship among A, B, and C, regardless of
 whether A, B, and C are individual elements or a list of elements.
 It is important to note that whereas the Information Elements and
 abstract data types defined in the IPFIX information model [RFC5102]
 represent single values, these new abstract data types are structural
 in nature and primarily contain references to other Information
 Elements and to Templates.  By referencing other Information Elements
 and Templates from an Information Element's data content, it is
 possible to define complex data structures such as variable-length
 lists and to specify hierarchical containment relationships between
 Templates.  Therefore, this document prefers the more generic "Data
 Record" term to the "Flow Record" term.
 This document specifies three new abstract data types, which are
 basic blocks to represent structured data.  However, this document
 does not comment on all possible combinations of basicList,
 subTemplateList, and subTemplateMultiList.  Neither does it limit the
 possible combinations.

3. Terminology

 IPFIX-specific terminology used in this document is defined in
 Section 2 of the IPFIX protocol specification [RFC5101] and Section 3
 of the PSAMP protocol specification [RFC5476].  As in [RFC5101],
 these IPFIX-specific terms have the first letter of a word
 capitalized when used in this document.

Claise, et al. Standards Track [Page 11] RFC 6313 Export of Structured Data in IPFIX July 2011

3.1. New Terminology

 Structured Data Information Element
    One of the Information Elements supporting structured data, i.e.,
    the basicList, subTemplateList, or subTemplateMultiList
    Information Elements specified in Section 4.3.

3.2. Conventions Used in This Document

 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
 document are to be interpreted as described in RFC 2119 [RFC2119].

4. Linkage with the IPFIX Information Model

 As in the IPFIX protocol specification [RFC5101], the new Information
 Elements specified in Section 4.3 MUST be sent in canonical format in
 network-byte order (also known as the big-endian byte ordering).

4.1. New Abstract Data Types

 This document specifies three new abstract data types, as described
 below.

4.1.1. basicList

 The type "basicList" represents a list of zero or more instances of
 any Information Element, primarily used for single-valued data types.
 Examples include a list of port numbers, a list of interface indexes,
 a list of AS in a BGP AS-PATH, etc.

4.1.2. subTemplateList

 The type "subTemplateList" represents a list of zero or more
 instances of a structured data type, where the data type of each list
 element is the same and corresponds with a single Template Record.
 Examples include a structured data type composed of multiple pairs of
 ("MPLS label stack entry position", "MPLS label stack value"), a
 structured data type composed of performance metrics, and a
 structured data type composed of multiple pairs of IP address, etc.

4.1.3. subTemplateMultiList

 The type "subTemplateMultiList" represents a list of zero or more
 instances of a structured data type, where the data type of each list
 element can be different and corresponds with different Template
 definitions.  Examples include a structured data type composed of

Claise, et al. Standards Track [Page 12] RFC 6313 Export of Structured Data in IPFIX July 2011

 multiple access-list entries, where entries can be composed of
 different criteria types.

4.2. New Data Type Semantic

 This document specifies a new data type semantic, in addition to the
 ones specified in Section 3.2 of the IPFIX information model
 [RFC5102], as described below.

4.2.1. List

 A list represents an arbitrary-length sequence of zero or more
 structured data Information Elements, either composed of regular
 Information Elements or composed of data conforming to a Template
 Record.

4.3. New Information Elements

 This document specifies three new Information Elements, as described
 below.

4.3.1. basicList

 A basicList specifies a generic Information Element with a basicList
 abstract data type as defined in Section 4.1.1 and list semantics as
 defined in Section 4.2.1.  Examples include a list of port numbers, a
 list of interface indexes, etc.

4.3.2. subTemplateList

 A subTemplateList specifies a generic Information Element with a
 subTemplateList abstract data type as defined in Section 4.1.2 and
 list semantics as defined in Section 4.2.1.

4.3.3. subTemplateMultiList

 A subTemplateMultiList specifies a generic Information Element with a
 subTemplateMultiList abstract data type as defined in Section 4.1.3
 and list semantics as defined in Section 4.2.1.

4.4. New Structured Data Type Semantics

 Structured data type semantics are provided in order to express the
 relationship among multiple list elements in a Structured Data
 Information Element.  These structured data type semantics require a
 new IPFIX subregistry, as specified in the "IANA Considerations"
 section.  The semantics are specified in the following subsections.

Claise, et al. Standards Track [Page 13] RFC 6313 Export of Structured Data in IPFIX July 2011

4.4.1. undefined

 The "undefined" structured data type semantic specifies that the
 semantic of list elements is not specified and that, if a semantic
 exists, then it is up to the Collecting Process to draw its own
 conclusions.  The "undefined" structured data type semantic, which is
 the default value, is used when no other structured data type
 semantic applies.
 For example, a mediator that wants to translate IPFIX [RFC5101] into
 the export of structured data according to the specifications in this
 document doesn't know what the semantic is; it can only guess, as the
 IPFIX specifications [RFC5101] does not contain any semantic.
 Therefore, the mediator should use the "undefined" semantic.

4.4.2. noneOf

 The "noneOf" structured data type semantic specifies that none of the
 elements are actual properties of the Data Record.
 For example, a mediator might want to report to a Collector that a
 specific Flow is suspicious, but that it checked already that this
 Flow does not belong to the attack type 1, attack type 2, or attack
 type 3.  So this Flow might need some further inspection.  In such a
 case, the mediator would report the Flow Record with a basicList
 composed of (attack type 1, attack type 2, attack type 3) and the
 respective structured data type semantic of "noneOf".
 Another example is a router that monitors some specific BGP AS-PATHs
 and reports if a Flow belongs to any of them.  If the router wants to
 export that a Flow does not belong to any of the monitored BGP AS-
 PATHs, the router reports a Data Record with a basicList composed of
 (BGP AS-PATH 1, BGP AS-PATH 2, BGP AS-PATH 3) and the respective
 structured data type semantic of "noneOf".

4.4.3. exactlyOneOf

 The "exactlyOneOf" structured data type semantic specifies that only
 a single element from the structured data is an actual property of
 the Data Record.  This is equivalent to a logical XOR operation.
 For example, if a Flow record contains a basicList of outgoing
 interfaces with the "exactlyOneOf" semantic, then it implies that the
 reported Flow only egressed from a single interface, although the
 Flow Record lists all of the possible outgoing interfaces.  This is a
 typical example of a per destination load-balancing.

Claise, et al. Standards Track [Page 14] RFC 6313 Export of Structured Data in IPFIX July 2011

 Another example is a mediator that must aggregate Data Records from
 different Observation Points and report an aggregated Observation
 Point.  However, the different Observation Points can be specified by
 different Information Element types depending on the Exporter.  For
 example:
    Exporter1 Observation Point is characterized by the
    exporterIPv4Address, so a specific Exporter can be represented.
    Exporter2 Observation Point is characterized by the
    exporterIPv4Address and a basicList of ingressInterface, so the
    Exporting Process can express that the observations were made on a
    series of input interfaces.
    Exporter3 Observation Point is characterized by the
    exporterIPv4Address and a specific lineCardId, so the Exporting
    Process can express that the observation was made on a specific
    linecard.
 If the mediator models the three different types of Observation
 Points with the three Template Records below:
    Template Record 1: exporterIPv4Address
    Template Record 2: exporterIPv4Address, basicList of
                       ingressInterface
    Template Record 3: exporterIPv4Address, lineCardId
 then it can represent the aggregated Observation Point with a
 subTemplateMultiList and the semantic "exactlyOneOf".  The aggregated
 Observation Point is modeled with the Data Records corresponding to
 either Template Record 1, Template Record 2, or Template Record 3 but
 not more than one of these.  This implies that the Flow was observed
 at exactly one of the Observation Points reported.

4.4.4. oneOrMoreOf

 The "oneOrMoreOf" structured data type semantic specifies that one or
 more elements from the list in the structured data are actual
 properties of the Data Record.  This is equivalent to a logical OR
 operation.
 Consider an example where a mediator must report an aggregated Flow
 (e.g., by aggregating IP addresses from IP prefixes), with an
 aggregated Observation Point.  However, the different Observation
 Points can be specified by different Information Element types as
 described in Section 4.4.2.

Claise, et al. Standards Track [Page 15] RFC 6313 Export of Structured Data in IPFIX July 2011

 If the mediator models the three different types of Observation
 Points with the three Template Records below:
        Template Record 1: exporterIPv4Address
        Template Record 2: exporterIPv4Address, basicList of
                           ingressInterface
        Template Record 3: exporterIPv4Address, lineCardId
 then it can represent the aggregated Observation Point with a
 subTemplateMultiList and the semantic "oneOrMoreOf".  The aggregated
 Observation Point is modeled with the Data Records corresponding to
 either Template Record 1, Template Record 2, or Template Record 3.
 This implies that the Flow was observed on at least one of the
 Observation Points reported, and potentially on multiple Observation
 Points.

4.4.5. allOf

 The "allOf" structured data type semantic specifies that all of the
 list elements from the structured data are actual properties of the
 Data Record.
 For example, if a Record contains a basicList of outgoing interfaces
 with the "allOf" semantic, then the observed Flow is typically a
 multicast Flow where each packet in the Flow has been replicated to
 each outgoing interface in the basicList.

4.4.6. ordered

 The "ordered" structured data type semantic specifies that elements
 from the list in the structured data are ordered.
 For example, an Exporter might want to export the AS10 AS20 AS30 AS40
 BGP AS-PATH.  In such a case, the Exporter would report a basicList
 composed of (AS10, AS20, AS30, AS40) and the respective structured
 data type semantic of "ordered".

4.5. Encoding of IPFIX Data Types

 The following subsections define the encoding of the abstract data
 types defined in Section 4.1.  These data types may be encoded using
 either fixed- or variable-length Information Elements, as discussed
 in Section 5.1.  Like in the IPFIX specifications [RFC5101], all
 lengths are specified in octets.

Claise, et al. Standards Track [Page 16] RFC 6313 Export of Structured Data in IPFIX July 2011

4.5.1. basicList

 The basicList Information Element defined in Section 4.3.1 represents
 a list of zero or more instances of an Information Element and is
 encoded as follows:
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |   Semantic    |0|          Field ID           |   Element...  |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 | ...Length     |           basicList Content ...               |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                     Figure 1: basicList Encoding
 Semantic
    The Semantic field indicates the relationship among the different
    Information Element values within this Structured Data Information
    Element.  Refer to IANA's "IPFIX Structured Data Types Semantics"
    registry.
 Field ID
    Field ID is the Information Element identifier of the Information
    Element(s) contained in the list.
 Element Length
    Per Section 7 of [RFC5101], the Element Length field indicates the
    length, in octets, of each list element specified by Field ID, or
    contains the value 0xFFFF if the length is encoded as a variable-
    length Information Element at the start of the basicList Content.
    Effectively, the Element Length field is part of the header, so
    even in the case of a zero-element list, it MUST NOT be omitted.
 basicList Content
    A Collecting Process decodes list elements from the basicList
    Content until no further data remains.  A field count is not
    included but can be derived when the Information Element is
    decoded.

Claise, et al. Standards Track [Page 17] RFC 6313 Export of Structured Data in IPFIX July 2011

 Note that in the diagram above, Field ID is shown with the Enterprise
 bit (most significant bit) set to 0.  Instead, if the Enterprise bit
 is set to 1, a four-byte Enterprise Number MUST be encoded
 immediately after the Element Length as shown below.  See the "Field
 Specifier Format" section in the IPFIX protocol [RFC5101] for
 additional information.
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |    Semantic   |1|         Field ID            |   Element...  |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 | ...Length     |               Enterprise Number ...           |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      ...      |              basicList Content ...            |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
         Figure 2: basicList Encoding with Enterprise Number
 Also, note that if a basicList has zero elements, the encoded data
 contains the Semantic field, Field ID, the Element Length field, and
 the four-byte Enterprise Number (if present), while the basicList
 Content is empty.
 If the basicList is encoded as a variable-length Information Element
 in less than 255 octets, it MAY be encoded with the Length field per
 Section 7 of [RFC5101] as shown in Figure 3.  However, the three-byte
 length encoding, as shown in Figure 4, is RECOMMENDED (see Section
 5.1).
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 | Length (< 255)|   Semantic    |0|          Field ID           |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |         Element Length        | basicList Content ...         |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      Figure 3: Variable-Length basicList Encoding
                    (Length < 255 Octets)

Claise, et al. Standards Track [Page 18] RFC 6313 Export of Structured Data in IPFIX July 2011

 If the basicList is encoded as a variable-length Information Element
 in 255 or more octets, it MUST be encoded with the Length field per
 Section 7 of [RFC5101] as follows:
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      255      |      Length (0 to 65535)      |   Semantic    |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0|          Field ID           |        Element Length         |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                      basicList Content ...                    |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   Figure 4: Variable-Length basicList Encoding
                (Length 0 to 65535 Octets)

4.5.2. subTemplateList

 The subTemplateList Information Element represents a list of zero or
 more Data Records corresponding to a specific Template.  Because the
 Template Record referenced by a subTemplateList Information Element
 can itself contain other subTemplateList Information Elements, and
 because these Template Record references are part of the Information
 Elements content in the Data Record, it is possible to represent
 complex hierarchical data structures.  The following diagram shows
 how a subTemplateList Information Element is encoded within a Data
 Record:
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |   Semantic    |         Template ID           |     ...       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                subTemplateList Content    ...                 |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                  Figure 5: subTemplateList Encoding

Claise, et al. Standards Track [Page 19] RFC 6313 Export of Structured Data in IPFIX July 2011

 Semantic
    The Semantic field indicates the relationship among the different
    Data Records within this Structured Data Information Element.
 Template ID
    The Template ID field contains the ID of the Template used to
    encode and decode the subTemplateList Content.
 subTemplateList Content
    subTemplateList Content consists of zero or more instances of Data
    Records corresponding to the Template ID specified in the Template
    ID field.  A Collecting Process decodes the subTemplateList
    Content until no further data remains.  A record count is not
    included but can be derived when the subTemplateList is decoded.
    Encoding and decoding are performed recursively if the specified
    Template itself contains Structured Data Information Elements as
    described here.
 Note that, if a subTemplateList has zero elements, the encoded data
 contains only the Semantic field and the Template ID field, while the
 subTemplateList Content is empty.
 If the subTemplateList is encoded as a variable-length Information
 Element in less than 255 octets, it MAY be encoded with the Length
 field per Section 7 of [RFC5101] as shown in Figure 6.  However, the
 three-byte length encoding, as shown in Figure 7, is RECOMMENDED (see
 Section 5.1).
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 | Length (< 255)|   Semantic    |         Template ID           |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                subTemplateList Content    ...                 |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   Figure 6: Variable-Length subTemplateList Encoding
                     (Length < 255 Octets)

Claise, et al. Standards Track [Page 20] RFC 6313 Export of Structured Data in IPFIX July 2011

 If the subTemplateList is encoded as a variable-length Information
 Element in 255 or more octets, it MUST be encoded with the Length
 field per Section 7 of [RFC5101] as follows:
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      255      |      Length (0 to 65535)      |   Semantic    |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |         Template ID           | subTemplateList Content ...   |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   Figure 7: Variable-Length subTemplateList Encoding
                  (Length 0 to 65535 Octets)

4.5.3. subTemplateMultiList

 Whereas each element in a subTemplateList Information Element
 corresponds to a single Template, it is sometimes useful for a list
 to contain elements corresponding to different Templates.  To support
 this case, each top-level element in a subTemplateMultiList
 Information Element carries a Template ID, Length, and zero or more
 Data Records corresponding to the Template ID.  The following diagram
 shows how a subTemplateMultiList Information Element is encoded
 within a Data Record.  Note that the encoding following the Semantic
 field is consistent with the Set Header specified in [RFC5101].
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |    Semantic   |         Template ID X         |Data Records...|
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 | ... Length X  |        Data Record X.1 Content ...            |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      ...      |        Data Record X.2 Content ...            |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      ...      |        Data Record X.L Content ...            |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      ...      |         Template ID Y         |Data Records...|
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Claise, et al. Standards Track [Page 21] RFC 6313 Export of Structured Data in IPFIX July 2011

 | ... Length Y  |        Data Record  Y.1 Content ...           |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      ...      |        Data Record Y.2 Content ...            |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      ...      |        Data Record Y.M Content ...            |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      ...      |         Template ID Z         |Data Records...|
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 | ... Length Z  |        Data Record Z.1 Content ...            |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      ...      |        Data Record Z.2 Content ...            |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      ...      |        Data Record Z.N Content ...            |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      ...      |
 +-+-+-+-+-+-+-+-+
              Figure 8: subTemplateMultiList Encoding
 Semantic
    The Semantic field indicates the top-level relationship among the
    series of Data Records corresponding to the different Template
    Records within this Structured Data Information Element.
 Template ID
    Unlike the subTemplateList Information Element, each element of
    the subTemplateMultiList contains a Template ID that specifies the
    encoding of the following Data Records.

Claise, et al. Standards Track [Page 22] RFC 6313 Export of Structured Data in IPFIX July 2011

 Data Records Length
    This is the total length of the Data Records encoding for the
    Template ID previously specified, including the two bytes for the
    Template ID and the two bytes for the Data Records Length field
    itself.
 Data Record X.M
    The Data Record X.M consists of the Mth Data Record of the
    Template Record X.  A Collecting Process decodes the Data Records
    according to Template Record X until no further data remains,
    according to the Data Records Length X.  Further Template IDs and
    Data Records may then be decoded according to the overall
    subTemplateMultiList length.  A record count is not included but
    can be derived when the Element Content is decoded.  Encoding and
    decoding are performed recursively if the specified Template
    itself contains Structured Data Information Elements as described
    here.
 In the exceptional case of zero instances in the
 subTemplateMultiList, no data is encoded, only the Semantic field and
 Template ID field(s), and the Data Record Length field is set to
 zero.
 If the subTemplateMultiList is encoded as a variable-length
 Information Element in less than 255 octets, it MAY be encoded with
 the Length field per Section 7 of [RFC5101] as shown in Figure 9.
 However, the three-byte length encoding, as shown in Figure 10, is
 RECOMMENDED (see Section 5.1).
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 | Length (< 255)|    Semantic   |         Template ID X         |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      Data Records Length X    |  Data Record X.1 Content ...  |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |             ...               |   Data Record X.2 Content ... |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |             ...               |   Data Record X.L Content ... |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Claise, et al. Standards Track [Page 23] RFC 6313 Export of Structured Data in IPFIX July 2011

 |             ...               |         Template ID Y         |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      Data Records Length Y    |   Data Record Y.1 Content ... |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |             ...               |   Data Record Y.2 Content ... |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |             ...               |   Data Record Y.M Content ... |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |             ...               |         Template ID Z         |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      Data Records Length Z    |   Data Record Z.1 Content ... |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |             ...               |   Data Record Z.2 Content ... |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |             ...               |   Data Record Z.N Content ... |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |             ...               |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    Figure 9: Variable-Length subTemplateMultiList Encoding
                    (Length < 255 Octets)
 If the subTemplateMultiList is encoded as a variable-length
 Information Element in 255 or more octets, it MUST be encoded with
 the Length field per Section 7 of [RFC5101] as follows:
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      255      |      Length (0 to 65535)      |   Semantic    |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |         Template ID X         |    Data Records Length X      |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                   Data Record X.1 Content ...                 |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |

Claise, et al. Standards Track [Page 24] RFC 6313 Export of Structured Data in IPFIX July 2011

 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                   Data Record X.2 Content ...                 |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                   Data Record X.L Content ...                 |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |         Template ID Y         |    Data Records Length Y      |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                   Data Record  Y.1 Content ...                |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                   Data Record Y.2 Content ...                 |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                   Data Record Y.M Content ...                 |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |         Template ID Z         |    Data Records Length Z      |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                     Data Record Z.1 Content ...               |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                     Data Record Z.2 Content ...               |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                     Data Record Z.N Content ...               |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   Figure 10: Variable-Length subTemplateMultiList Encoding
                      (Length 0 to 65535 Octets)

5. Structured Data Format

5.1. Length Encoding Considerations

 The new Structured Data Information Elements represent a list that
 potentially carries complex hierarchical and repeated data.

Claise, et al. Standards Track [Page 25] RFC 6313 Export of Structured Data in IPFIX July 2011

 When the encoding of a Structured Data Information Element has a
 fixed length (because, for example, it contains the same number of
 fixed-length elements, or if the permutations of elements in the list
 always produces the same total length), the element length can be
 encoded in the corresponding Template Record.
 However, when representing variable-length data, hierarchical data,
 and repeated data with variable element counts, where the number and
 length of elements can vary from record to record, we RECOMMEND that
 the Information Elements are encoded using the variable-length
 encoding described in Section 7 of [RFC5101], with the length carried
 before the Structured Data Information Element encoding.
 Because of the complex and repeated nature of the data, it is
 potentially difficult for the Exporting Process to efficiently know
 in advance the exact encoding size.  In this case, the Exporting
 Process may encode the available data starting at a fixed offset and
 fill in the final length afterwards.  Therefore, the three-byte
 length encoding is RECOMMENDED for variable-length Information
 Elements in all Template Records containing a Structured Data
 Information Element, even if the encoded length can be less than 255
 bytes, because the starting offset of the data is known in advance.
 When encoding such data, an Exporting Process MUST take care to not
 exceed the maximum allowed IPFIX message length of 65535 bytes as
 specified in [RFC5101].

5.2. Recursive Structured Data

 It is possible to define recursive relationships between IPFIX
 structured data instances, for example, when representing a tree
 structure.  The simplest case of this might be a basicList, where
 each element is itself a basicList, or a subTemplateList where one of
 the fields of the referenced Template is itself a subTemplateList
 referencing the same Template.  Also, the Exporting Process MUST take
 care when encoding recursively-defined structured data not to exceed
 the maximum allowed length of an IPFIX Message (as noted in Length
 Encoding Considerations).

5.3. Structured Data Information Elements Applicability in Options

    Template Sets
 Structured Data Information Elements MAY be used in Options Template
 Sets.
 As an example, consider a mediation function that must aggregate Data
 Records from multiple Observation Point types:

Claise, et al. Standards Track [Page 26] RFC 6313 Export of Structured Data in IPFIX July 2011

    Router 1, (interface 1)
    Router 2, (linecard A)
    Router 3, (linecard B)
    Router 4, (linecard C, interface 2)
 In order to encode the PSAMP Selection Sequence Report Interpretation
 [RFC5476], the mediation function must express this combination of
 Observation Points as a single new Observation Point.  Recall from
 [RFC5476] that the PSAMP Selection Sequence Report Interpretation
 consists of the following fields:
   Scope:     selectionSequenceId
   Non-Scope: one Information Element mapping the Observation Point
              selectorId (one or more)
 Without structured data, there is clearly no way to express the
 complex aggregated Observation Point as "one Information Element
 mapping the Observation Point".  However, the desired result may be
 easily achieved using the structured data types.  Refer to Section
 9.5. for an encoding example related to this case study.
 Regarding the scope in the Options Template Record, the IPFIX
 specification [RFC5101] mentions that "the IPFIX protocol doesn't
 prevent the use of any Information Elements for scope".  Therefore, a
 Structured Data Information Element MAY be used as scope in an
 Options Template Set.
 Extending the previous example, the mediation function could export a
 given name for this complex aggregated Observation Point:
    Scope: Aggregated Observation Point (structured data)
    Non-Scope: a new Information Element containing the name

5.4. Usage Guidelines for Equivalent Data Representations

 Because basicList, subTemplateList, and subTemplateMultiList are all
 lists, in several cases, there is more than one way to represent what
 is effectively the same data structure.  However, in some cases, one
 approach has an advantage over the other, e.g., more compact, uses
 fewer resources, and is therefore preferred over an alternate
 representation.
 A subTemplateList can represent the same simple list of single-valued
 Information Elements as a basicList, if the Template referenced by
 the subTemplateList contains only one single-valued Information
 Element.  Although the encoding is more compact than a basicList by
 two bytes, using a subTemplateList, in this case, requires a new

Claise, et al. Standards Track [Page 27] RFC 6313 Export of Structured Data in IPFIX July 2011

 Template per Information Element.  The basicList requires no
 additional Template and is therefore RECOMMENDED in this case.
 Although a subTemplateMultiList with one Element can represent the
 contents of a subTemplateList, the subTemplateMultiList carries two
 additional bytes (Element Length).  It is also potentially useful to
 a Collecting Process to know in advance that a subTemplateList
 directly indicates that list element types are consistent.  The
 subTemplateList Information Element is therefore RECOMMENDED in this
 case.
 The Semantic field in a subTemplateMultiList indicates the top-level
 relationship among the series of Data Records corresponding to the
 different Template Records, within this Structured Data Information
 Element.  If a semantic is required to describe the relationship
 among the different Data Records corresponding to a single Template
 ID within the subTemplateMultiList, then an encoding based on a
 basicList of subTemplateLists should be used; refer to Section 5.6
 for more information.  Alternatively, if a semantic is required to
 describe the relationship among all Data Records within a
 subTemplateMultiList (regardless of the Template Record), an encoding
 based on a subTemplateMultiList with one Data Record corresponding to
 a single Template ID can be used.
 Note that the referenced Information Element(s) in the Structured
 Data Information Elements can be taken from the IPFIX information
 model [RFC5102], the PSAMP information model [RFC5477], any of the
 Information Elements defined in the IANA IPFIX registry [IANA-IPFIX],
 or enterprise-specific Information Elements.
 If a Template Record contains a subTemplateList as the only field, a
 Set encoding as specified in the IPFIX protocol specifications
 [RFC5101] should be considered, unless:
  1. A relationship among multiple list elements must be exported, in

which case, the semantic from the IPFIX Structured Data Information

   Element can convey this relationship.
  1. The Exporting Process wants to convey the number of elements in the

list, even in the special cases of zero or one element in the list.

   Indeed, the case of an empty list cannot be represented with the
   IPFIX protocol specifications [RFC5101].  In the case of a single
   element list, the Template Record specified in the IPFIX protocol
   specification [RFC5101] could be used.  However, on the top of the
   Template Record with the subTemplateList to export multiple list
   elements, this supplementary Template would impose some extra

Claise, et al. Standards Track [Page 28] RFC 6313 Export of Structured Data in IPFIX July 2011

   management, both on the Exporting Process and on the Collecting
   Process, which might have to correlate the information from two
   Template Records.
 Similarly, if a Template Record contains a subTemplateMultiList as
 the only field, an IPFIX Message as described in the IPFIX protocol
 specification [RFC5101] should be considered, unless:
  1. A relationship among top-level list elements must be exported, in

which case, the semantic from the IPFIX Structured Data Information

   Element can convey this relationship.
  1. The Exporting Process wants to convey the number of Data Records

corresponding to every Template in the subTemplateMultiList.

5.5. Padding

 The Exporting Process MAY insert some padding octets in structured
 data field values in a Data Record by including the 'paddingOctets'
 Information Element as described in [RFC5101], Section 3.3.1.  The
 paddingOctets Information Element can be included in a Template
 Record referenced by a structured data Information Element for this
 purpose.

5.6. Semantic

 Semantic interpretations of received Data Records at or beyond the
 Collecting Process remain explicitly undefined, unless that data is
 transmitted using this extension with explicit structured data type
 semantic information.
 It is not the Exporter's role to check the validity of the semantic
 representation of Data Records.
 More complex semantics can be expressed as a combination of the
 Semantic Data Information Elements specified in this document.
 For example, the export of the AS10 AS20 AS30 AS40 {AS50,AS60} BGP
 AS-PATH would be reported as a basicList of two elements, each
 element being a basicList of BGP AS, with the top-level structured
 data type semantic of "ordered".  The first element would contain a
 basicList composed of (AS10,AS20,AS30,AS40) and the respective
 structured data type semantic of "ordered", while the second element
 would contain a basicList composed of (AS50, AS60) and the respective
 structured data type semantic of "exactlyOneOf".  A high-level Data
 Record diagram would be represented as:

Claise, et al. Standards Track [Page 29] RFC 6313 Export of Structured Data in IPFIX July 2011

      BGP AS-PATH = (basicList, ordered,
          (basicList, ordered, AS10,AS20,AS30,AS40),
          (basicList, exactlyOneOf, AS50, AS60)
      )
 If a semantic is required to describe the relationship among the
 different Data Records corresponding to a single Template ID within
 the subTemplateMultiList, then an encoding based on a basicList of
 subTemplateLists should be used, as shown in the next case study.
  Case study 1:
 In this example, an Exporter monitoring security attacks must export
 a list of security events consisting of attackers and targets.  For
 the sake of the example, assume that the Collector can differentiate
 the attacker (which is expressed using source fields) from the target
 (which is expressed using destination fields).  Imagine that
 attackers A1 or A2 may attack targets T1 and T2.
 The first case uses a subTemplateMultiList composed of two Template
 Records, one representing the attacker and one representing the
 target, each of them containing an IP address and a port.
      Attacker Template Record = (src IP address, src port)
      Target Template Record = (dst IP address, dst port)
 A high-level Data Record diagram would be represented as:
       Alert = (subTemplateMultiList, allOf,
          (Attacker Template Record, A1, A2),
          (Target Template Record, T1, T2)
       )
 The Collecting Process can only conclude that the list of attackers
 (A1, A2) and the list of targets (T1, T2) are present, without
 knowing the relationship amongst attackers and targets.  The
 Exporting Process would have to explicitly call out the relationship
 amongst attackers and targets as the top-level semantic offered by
 the subTemplateMultiList isn't sufficient.

Claise, et al. Standards Track [Page 30] RFC 6313 Export of Structured Data in IPFIX July 2011

 The only proper encoding for the previous semantic (i.e., attacker A1
 or A2 may attack target T1 and T2) uses a basicList of
 subTemplateLists and is represented as follows:
      Attacker Template Record = (src IP address, src port)
      Target Template Record = (dst IP address, dst port)
      Alert = (basicList, allOf,
            (subTemplateList, exactlyOneOf, attacker A1, A2)
            (subTemplateList, allOf, target T1, T2)
      )
  Case study 2:
 In this example, an Exporter monitoring security attacks must export
 a list of attackers and targets.  For the sake of the example, assume
 that the Collector can differentiate the attacker (which is expressed
 using source fields) from the target (which is expressed using
 destination fields).  Imagine that attacker A1 or A2 is attacking
 target T1, while attacker A3 is attacking targets T2 and T3.  The
 first case uses a subTemplateMultiList that contains Data Records
 corresponding to two Template Records, one representing the attacker
 and one representing the target, each of them containing an IP
 address and a port.
      Attacker Template Record = (src IP address, src port)
      Target Template Record = (dst IP address, dst port)
 A high-level Data Record diagram would be represented as:
       Alert = (subTemplateMultiList, allOf,
          (Attacker Template Record, A1, A2, A3),
          (Target Template Record, T1, T2, T3)
       )
 The Collecting Process can only conclude that the list of attackers
 (A1, A2, A3), and the list of targets (T1, T2, T3) are present,
 without knowing the relationship amongst attackers and targets.

Claise, et al. Standards Track [Page 31] RFC 6313 Export of Structured Data in IPFIX July 2011

 The second case could use a Data Record definition composed of the
 following:
       Alert = (subTemplateMultiList, allOf,
          (Attacker Template Record, A1, A2),
          (Target Template Record, T1),
          (Attacker Template Record, A3),
          (Target Template Record, T2, T3)
       )
 With the above representation, the Collecting Process can infer that
 the alert consists of the list of attackers (A1, A2), target (T1),
 attacker (A3), and list of targets (T2, T3).  From the sequence in
 which attackers and targets are encoded, the Collector can possibly
 deduce that some relationship exists among (A1, A2, T1) and (A2, T1,
 T2) but cannot understand what it is exactly.  So, there is a need
 for the Exporting Process to explicitly define the relationship
 between the attackers, and targets and the top-level semantic of the
 subTemplateMultiList is not sufficient.
 The only proper encoding for the previous semantic (i.e., attacker A1
 or A2 attacks target T1, attacker A3 attacks targets T2 and T3) uses
 a basicList of subTemplateLists and is represented as follows:
      Participant P1 =
      (basicList, allOf,
            (subTemplateList, exactlyOneOf, attacker A1, A2)
            (subTemplateList, undefined, target T1)
      )
      Participant P2 =
      (basicList, allOf,
            (subTemplateList, undefined, attacker A3,
            (subTemplateList, allOf, targets T2, T3)
      )

Claise, et al. Standards Track [Page 32] RFC 6313 Export of Structured Data in IPFIX July 2011

 The security alert is represented as a subTemplateList of
 participants.
      Alert =
         (subTemplateList, allOf, Participant P1, Participant P2)
 Note that, in the particular case of a single element in a Structured
 Data Information Element, the Semantic field is actually not very
 useful since it specifies the relationship among multiple elements.
 Any choice of allOf, exactlyOneOf, or OneOrMoreOf would provide the
 same result semantically.  Therefore, in case of a single element in
 a Structured Data Information Element, the default "undefined"
 semantic SHOULD be used.

6. Template Management

 This section introduces some more specific Template management and
 Template Withdrawal Message-related specifications compared to the
 IPFIX protocol specification [RFC5101].
 First of all, the Template ID uniqueness is unchanged compared to
 [RFC5101]; the uniqueness is local to the Transport Session and
 Observation Domain that generated the Template ID.  In other words,
 the Set ID used to export the Template Record does not influence the
 Template ID uniqueness.
 While [RFC5101] mentions that "if an Information Element is required
 more than once in a Template, the different occurrences of this
 Information Element SHOULD follow the logical order of their
 treatments by the Metering Process", this rule MAY be ignored within
 Structured Data Information Elements.
 As specified in [RFC5101], Templates that are not used anymore SHOULD
 be deleted.  Deleting a Template implies that it MUST NOT be used
 within subTemplateList and subTemplateMultiList anymore.  Before
 reusing a Template ID, the Template MUST be deleted.  In order to
 delete an allocated Template, the Template is withdrawn through the
 use of a Template Withdrawal Message.

7. The Collecting Process's Side

 This section introduces some more specific specifications to the
 Collection Process compared to Section 9 in the IPFIX protocol
 [RFC5101].
 As opposed to the IPFIX specification in [RFC5101], IPFIX Messages
 with IPFIX Structured Data Information Elements change the IPFIX

Claise, et al. Standards Track [Page 33] RFC 6313 Export of Structured Data in IPFIX July 2011

 concept from the Collector's point of view as the data types are
 present in the Data Records rather than in the Template Records.  For
 example, a basicList Information Element in a Template Record doesn't
 specify the list element data type; this information is contained in
 the Data Record.  For example, in case of a subTemplateMultiList, the
 Collecting Process must refer to the included Template Records in the
 middle of the Data Record decode.
 As described in [RFC5101], a Collecting Process MUST note the
 Information Element identifier of any Information Element that it
 does not understand and MAY discard that Information Element from the
 Flow Record.  Therefore, a Collection Process that does not support
 the extension specified in this document can ignore the Structured
 Data Information Elements in a Data Record, or it can ignore Data
 Records containing these new Structured Data Information Elements
 while continuing to process other Data Records.
 If the structured data contains the "undefined" structured data type
 semantic, the Collecting Process MAY attempt to draw its own
 conclusion in terms of the semantic contained in the Data Record.

8. Defining New Information Elements Based on the New Abstract Data

  Types
 This document specifies three new abstract data types: basicList,
 subTemplateList, and subTemplateMultiList.  As specified in
 [RFC5102], the specification of new IPFIX Information Elements uses
 the Template specified in Section 2.1 of [RFC5102].  This Template
 mentioned existing and future the data types: "One of the types
 listed in Section 3.1 of this document or in a future extension of
 the information model".  So new Information Elements can be specified
 based on the three new abstract data types.
 The authors anticipate the creation of both enterprise-specific and
 IANA Information Elements based on the IPFIX structured data types.
 For example, bgpPathList, bgpSequenceList, and bgpSetList, of
 abstract types and semantics basicList/ordered, basicList/ordered,
 and basicList/exactlyOneOf respectively, would define the complete
 semantic of the list.  This specification doesn't specify any new
 Information Elements beyond the ones in Section 4.3.

9. Structured Data Encoding Examples

 The following examples are created solely for the purpose of
 illustrating how the extensions proposed in this document are
 encoded.

Claise, et al. Standards Track [Page 34] RFC 6313 Export of Structured Data in IPFIX July 2011

9.1. Encoding a Multicast Data Record with basicList

 Consider encoding a multicast Data Record containing the following
 data:
  1. ————————————————————–

Ingress If | Source IP | Destination IP | Egress Interfaces

  1. ————————————————————–

9 192.0.2.201 233.252.0.1 1, 4, 8

  1. ————————————————————–
 Template Record for the multicast Flows, with the Template ID 256:
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |         Set ID = 2            |      Length = 24 octets       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |       Template ID = 256       |       Field Count = 4         |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0|    ingressInterface = 10    |       Field Length = 4        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0|   sourceIPv4Address = 8     |       Field Length = 4        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0| DestinationIPv4Address = 12 |       Field Length = 4        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0|       basicList = 291       |     Field Length = 0xFFFF     |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
            Figure 11: Encoding basicList, Template Record
 The list of outgoing interfaces is represented as a basicList with
 semantic allOf, and the Length of the list is chosen to be encoded in
 three bytes even though it may be less than 255 octets.

Claise, et al. Standards Track [Page 35] RFC 6313 Export of Structured Data in IPFIX July 2011

 The Data Set is represented as follows:
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |          Set ID = 256         |          Length = 36          |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                     ingressInterface = 9                      |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |               sourceIPv4Address = 192.0.2.201                 |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |             DestinationIPv4Address = 233.252.0.1              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      255      |        List Length = 17       | semantic=allOf|
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 | egressInterface FieldId = 14  |egressInterface Field Length=4 |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                egressInterface value 1 = 1                    |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                egressInterface value 2 = 4                    |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                egressInterface value 3 = 8                    |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      Figure 12: Encoding basicList, Data Record, Semantic allOf
 In the example above, the basicList contains fixed-length elements.
 To illustrate how variable-length elements would be encoded, the same
 example is shown below with variable-length interface names in the
 basicList instead:

Claise, et al. Standards Track [Page 36] RFC 6313 Export of Structured Data in IPFIX July 2011

  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |          Set ID = 256         |          Length = 44          |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                     ingressInterface = 9                      |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |               sourceIPv4Address = 192.0.2.201                 |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |             DestinationIPv4Address = 233.252.0.1              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      255      |        List Length = 25       | semantic=allOf|
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0| InterfaceName FieldId = 82  | InterfaceName Field Len=0xFFFF|
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |  Length = 5   |      'F'      |      'E'      |      '0'      |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |     '/'       |      '0'      |  Length = 7   |      'F'      |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |     'E'       |      '1'      |      '0'      |      '/'      |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |     '1'       |      '0'      |  Length = 5   |      'F'      |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |     'E'       |      '2'      |     '/'       |      '2'      |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  Figure 13: Encoding basicList, Data Record with Variable-Length
                     Elements, Semantic allOf

9.2. Encoding a Load-Balanced Data Record with a basicList

 Consider encoding a load-balanced Data Record containing the
 following data:
  1. ————————————————————–

Ingress If | Source IP | Destination IP | Egress Interfaces

  1. ————————————————————–

9 192.0.2.201 233.252.0.1 1, 4, 8

  1. ————————————————————–

Claise, et al. Standards Track [Page 37] RFC 6313 Export of Structured Data in IPFIX July 2011

 So the Data Record egressed from either interface 1, 4, or 8.  The
 Data Set is represented as follows:
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |          Set ID = 256         |          Length = 36          |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                     ingressInterface = 9                      |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |               sourceIPv4Address = 192.0.2.201                 |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |             DestinationIPv4Address = 233.252.0.1              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      255      |        List Length = 17       |sem=exactlyOne |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 | egressInterface FieldId = 14  |egressInterface Field Length=4 |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                egressInterface value 1 = 1                    |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                egressInterface value 2 = 4                    |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                egressInterface value 3 = 8                    |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       Note: sem=exactlyOne represents semantic=exactlyOneOf
   Figure 14: Encoding basicList, Data Record, Semantic exactlyOneOf

9.3. Encoding subTemplateList

 As explained in Section 2.2, multiple pairs of
 (observationTimeMicroseconds, digestHashValue) must be collected from
 two different Observation Points to passively compute the one-way
 delay across the network.  This data can be exported with an
 optimized Data Record that consists of the following attributes:
     5-tuple
               { observationTimeMicroseconds 1, digestHashValue 1 }
               { observationTimeMicroseconds 2, digestHashValue 2 }
               { observationTimeMicroseconds 3, digestHashValue 3 }
               { ...  , ... }
 A subTemplateList is best suited for exporting the list of
 (observationTimeMicroseconds, digestHashValue).  For illustration
 purposes, the number of elements in the list is 5; in practice, it
 could be more.

Claise, et al. Standards Track [Page 38] RFC 6313 Export of Structured Data in IPFIX July 2011

  1. —————————————————————–

srcIP | dstIP | src | dst |proto| one-way delay

           |            | Port  | Port |     |   metrics
 ------------------------------------------------------------------
 192.0.2.1  192.0.2.105   1025     80     6    Time1, 0x0x91230613
                                               Time2, 0x0x91230650
                                               Time3, 0x0x91230725
                                               Time4, 0x0x91230844
                                               Time5, 0x0x91230978
 ------------------------------------------------------------------
 The following Template is defined for exporting the one-way delay
 metrics:
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |        Set ID = 2             |      Length = 16 octets       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |       Template ID = 257       |       Field Count = 2         |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0| observationTimeMicroSec=324 |       Field Length = 8        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0|   digestHashValue = 326     |       Field Length = 4        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    Figure 15: Encoding subTemplateList, Template for One-Way Delay
                               Metrics

Claise, et al. Standards Track [Page 39] RFC 6313 Export of Structured Data in IPFIX July 2011

 The Template Record for the Optimized Data Record is as follows:
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |         Set ID = 2            |      Length = 32 octets       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |       Template ID = 258       |       Field Count = 6         |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0|   sourceIPv4Address = 8     |       Field Length = 4        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0| destinationIPv4Address = 12 |       Field Length = 4        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0|  sourceTransportPort = 7    |       Field Length = 2        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0| destinationTransportPort= 11|       Field Length = 2        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0| protocolIdentifier = 4      |       Field Length = 1        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0|  subTemplateList = 292      |     Field Length = 0xFFFF     |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
         Figure 16: Encoding subTemplateList, Template Record
 The list of (observationTimeMicroseconds, digestHashValue) is
 exported as a subTemplateList with semantic allOf.  The Length of the
 subTemplateList is chosen to be encoded in three bytes even though it
 may be less than 255 octets.
 The Data Record is represented as follows:
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |         Set ID = 258          |      Length = 83 octets       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                sourceIPv4Address = 192.0.2.1                  |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |              destinationIPv4Address = 192.0.2.105             |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 | sourceTransportPort = 1025    | destinationTransportPort = 80 |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 | Protocol = 6  |      255      | one-way metrics list len = 63 |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 | semantic=allOf|       TemplateID = 257        | TimeValue1    |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                 ... octets 2-5 of TimeValue1                  |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Claise, et al. Standards Track [Page 40] RFC 6313 Export of Structured Data in IPFIX July 2011

 |          ... octets 6-8 of TimeValue1         |digestHashVal1=|
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                ... 0x0x91230613               | TimeValue2    |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                 ... octets 2-5 of TimeValue2                  |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |          ... octets 6-8 of TimeValue2         |digestHashVal2=|
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                ... 0x0x91230650               | TimeValue3    |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                 ... octets 2-5 of TimeValue3                  |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |          ... octets 6-8 of TimeValue3         |digestHashVal3=|
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                ... 0x0x91230725               | TimeValue4    |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                 ... octets 2-5 of TimeValue4                  |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |          ... octets 6-8 of TimeValue4         |digestHashVal4=|
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                ... 0x0x91230844               | TimeValue5    |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                 ... octets 2-5 of TimeValue5                  |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |          ... octets 6-8 of TimeValue5         |digestHashVal5=|
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                ... 0x0x91230978               |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
              Figure 17: Encoding subTemplateList, Data Set

9.4. Encoding subTemplateMultiList

 As explained in Section 4.5.3, a subTemplateMultiList is used to
 export a list of mixed-type content where each top-level element
 corresponds to a different Template Record.
 To illustrate this, consider the Data Record with the following
 attributes:

Claise, et al. Standards Track [Page 41] RFC 6313 Export of Structured Data in IPFIX July 2011

      5-tuple (Flow Keys), octetCount, packetCount
                attributes for filtering
                     selectorId,
                     selectorAlgorithm
                attributes for sampling
                     selectorId,
                     selectorAlgorithm,
                     samplingPacketInterval,
                     samplingPacketSpace
 This example demonstrates that the Selector Report Interpretation
 [RFC5476] can be encoded with the subTemplateMultiList.  More
 specifically, the example describes Property Match Filtering Selector
 Report Interpretation [RFC5476] used for filtering purposes, and the
 Systemic Count-Based Sampling as described in Section 6.5.2.1 of
 [RFC5476].  Some traffic will be filtered according to match
 properties configured, some will be sampled, some will be filtered
 and sampled, and some will not be filtered or sampled.
 A subTemplateMultiList is best suited for exporting this variable
 data.  A Template is defined for filtering attributes and another
 Template is defined for sampling attributes.  A Data Record can
 contain data corresponding to either of the Templates, both of them,
 or neither of them.
 Consider the example below where the following Data Record contains
 both filtering and sampling attributes.
 Key attributes of the Data Record:
  1. —————————————————————–

srcIP | dstIP | src | dst | proto | octetCount | packet

            |           | Port | Port |       |            | Count
 ------------------------------------------------------------------
 2001:DB8::1 2001:DB8::2  1025    80      6       108000      120
 ------------------------------------------------------------------
 Filtering attributes:
  1. ——————————————

selectorId | selectorAlgorithm

  1. ——————————————

100 5 (Property Match Filtering)

  1. ——————————————

Claise, et al. Standards Track [Page 42] RFC 6313 Export of Structured Data in IPFIX July 2011

 Sampling attributes:
 For Systemic Count-Based Sampling as defined in Section 6.5.2.1 of
 [RFC5476] the required algorithm-specific Information Elements are:
       samplingPacketInterval: number of packets selected in a row
       samplingPacketSpace:    number of packets between selections
 Example of a simple 1-out-of-100 systematic count-based Selector
 definition, where the samplingPacketInterval is 1 and the
 samplingPacketSpace is 99.
  1. ————————————————————-

selectorId | selectorAlgorithm | sampling | sampling

            |                          | Packet   | Packet
            |                          | Interval | Space
 --------------------------------------------------------------
    15        1 (Count-Based Sampling)      1         99
 --------------------------------------------------------------
 To represent the Data Record, the following Template Records are
 defined:
     Template for filtering attributes: 259
      Template for sampling attributes: 260
      Template for Flow Record: 261
      Flow record (261)
          |  (sourceIPv6Address)
          |  (destinationIPv6Address)
          |  (sourceTransportPort)
          |  (destinationTransportPort)
          |  (protocolIdentifier)
          |  (octetTotalCount)
          |  (packetTotalCount)
          |
          +------ filtering attributes (259)
          |          (selectorId)
          |          (selectorAlgorithm)
          |
          +------ sampling attributes (260)
          |          (selectorId)
          |          (selectorAlgorithm)
          |          (samplingPacketInterval)
          |          (samplingPacketSpace)

Claise, et al. Standards Track [Page 43] RFC 6313 Export of Structured Data in IPFIX July 2011

 The following Template Record is defined for filtering attributes:
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |          Set ID = 2           |          Length = 16          |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      Template ID = 259        |        Field Count = 2        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0|    selectorId = 302         |        Field Length = 4       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0| selectorAlgorithm = 304     |        Field Length = 1       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  Figure 18: Encoding subTemplateMultiList, Template for Filtering
                             Attributes
 The Template for sampling attributes is defined as follows:
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |          Set ID = 2           |          Length = 24          |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      Template ID = 260        |        Field Count = 4        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0|    selectorId = 302         |        Field Length = 4       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0|  selectorAlgorithm = 304    |        Field Length = 1       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0| samplingPacketInterval = 305|        Field Length = 1       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0| samplingPacketSpace = 306   |        Field Length = 1       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   Figure 19: Encoding subTemplateMultiList, Template for Sampling
                             Attributes
 Note that while selectorAlgorithm is defined as unsigned16, and
 samplingPacketInterval and samplingPacketSpace are defined as
 unsigned32, they are compressed down to 1 octet here as allowed by
 Reduced Size Encoding in Section 6.2 of the IPFIX protocol
 specifications [RFC5101].

Claise, et al. Standards Track [Page 44] RFC 6313 Export of Structured Data in IPFIX July 2011

 Template for the Flow Record is defined as shown below:
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |          Set ID = 2           |          Length = 40          |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      Template ID = 261        |        Field Count = 8        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0|   sourceIPv6Address = 27    |       Field Length = 16       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0| destinationIPv6Address = 28 |       Field Length = 16       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0| sourceTransportPort = 7     |       Field Length = 2        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0| destinationTransportPort=11 |       Field Length = 2        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0| protocolIdentifier = 4      |       Field Length = 1        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0|   octetTotalCount = 85      |       Field Length = 4        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0|   packetTotalCount = 86     |       Field Length = 4        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0| subTemplateMultiList = 293  |     Field Length = 0XFFFF     |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 Figure 20: Encoding subTemplateMultiList, Template for Flow Record
 A subTemplateMultiList with semantic allOf is used to export the
 filtering and sampling attributes.  The Length field of the
 subTemplateMultiList is chosen to be encoded in three bytes even
 though it may be less than 255 octets.
 The Data Record is encoded as follows:
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |       Set ID = 261            |          Length = 73          |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                      sourceIPv6Address =        ...           |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                          2001:DB8::1                          |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Claise, et al. Standards Track [Page 45] RFC 6313 Export of Structured Data in IPFIX July 2011

 |                   destinationIPv6Address =      ...           |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                              ...                              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                          2001:DB8::2                          |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |  sourceTransportPort = 1025   | destinationTransportPort = 80 |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 | protocol = 6  |        octetTotalCount = 108000               |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |     ...       |        packetTotalCount = 120                 |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |     ...       |      255      | Attributes List Length = 21   |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |semantic=allOf | Filtering Template ID = 259   |Filtering Attr |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 | ...Length = 9 |              selectorId = ...                 |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 | ...  100      |selectorAlg = 5|  Sampling Template ID = 260   |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 | Sampling Attributes Length=11 |         selectorId = ...      |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |  ...         15               |selectorAlg = 1|  Interval = 1 |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 | Space = 99    |
 +-+-+-+-+-+-+-+-+
         Figure 21: Encoding subTemplateMultiList, Data Set

9.5. Encoding an Options Template Set Using Structured Data

 As described in Section 5.3, consider a mediation function that must
 aggregate Data Records from different Observation Points.
 Say Observation Point 1 consists of one or more interfaces,
 Observation Points 2 and 3 consist of one or more linecards, and
 Observation Point 4 consists of one or more interfaces and one or
 more linecards.  Without structured data, a Template would have to be
 defined for every possible combination to interpret the data
 corresponding to each of the Observation Points.  However, with
 structured data, a basicList can be used to encode the list of
 interfaces and another basicList can be used to encode the list of
 linecards.

Claise, et al. Standards Track [Page 46] RFC 6313 Export of Structured Data in IPFIX July 2011

 For the sake of simplicity, each Observation Point shown below has
 the IP address corresponding to the Router and an <interface> or
 <linecard> or <linecard and interface>.  This can very well be
 extended to include a list of interfaces and a list of linecards
 using basicLists as explained above.
    Observation Point 1: Router 1, (interface 1)
    Observation Point 2: Router 2, (linecard A)
    Observation Point 3: Router 3, (linecard B)
    Observation Point 4: Router 4, (linecard C, interface 2)
 The mediation function wishes to express this as a single Observation
 Point, in order to encode the PSAMP Selection Sequence Report
 Interpretation (SSRI).  Recall from [RFC5476] that the PSAMP
 Selection Sequence Report Interpretation consists of the following
 fields:
   Scope:     selectionSequenceId
   Non-Scope: one Information Element mapping the
              Observation Point
              selectorId (one or more)
 For example, the Observation Point detailed above may be encoded in a
 PSAMP Selection Sequence Report Interpretation as shown below:
  Selection Sequence 7 (Filter->Sampling):
   Observation Point: subTemplateMultiList.
    Router 1 (IP address = 192.0.2.11), (interface 1)
    Router 2 (IP address = 192.0.2.12), (linecard A)
    Router 3 (IP address = 192.0.2.13), (linecard B)
    Router 4 (IP address = 192.0.2.14), (linecard C, interface 2)
    selectorId: 5 (Filter, match IPv4SourceAddress 192.0.2.1)
    selectorId: 10 (Sampler, Random 1 out-of ten)
 The following Templates are defined to represent the PSAMP SSRI:
 Template for representing PSAMP SSRI: 262
 Template for representing interface: 263
 Template for representing linecard: 264
 Template for representing linecard and interface: 265

Claise, et al. Standards Track [Page 47] RFC 6313 Export of Structured Data in IPFIX July 2011

     PSAMP SSRI (262)
         | (SelectionSequenceId)
         |
         +--- Observation Point 1 (263)
         |      (exporterIPv4Address)
         |      (Interface Id)
         |
         +--- Observation Point 2 and 3 (264)
         |      (exporterIPv4Address)
         |      (linecard)
         |
         +--- Observation Point 4 (265)
         |      (exporterIPv4Address)
         |      (linecard)
         |      (Interface Id)
         |
         | (selectorId 1)
         | (selectorId 2)
 Note that the example could further be improved with a basicList
 of selectorId if many Selector IDs have to be reported.
                  Figure 22: PSAMP SSRI to Be Encoded
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |          Set ID = 3           |          Length = 26          |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |        Template ID = 262      |         Field Count = 4       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |     Scope Field Count =  1    |0|  selectionSequenceId = 301  |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |       Scope 1 Length = 4      |0| subTemplateMultiList =  293 |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |     Field Length = 0xFFFF     |0|      selectorId = 302       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |        Field Length = 4       |0|      selectorId = 302       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |        Field Length = 4       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       Figure 23: Options Template Record for PSAMP SSRI Using
                        subTemplateMultiList
 A subTemplateMultiList with semantic allOf is used to encode the
 list of Observation Points.

Claise, et al. Standards Track [Page 48] RFC 6313 Export of Structured Data in IPFIX July 2011

  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |          Set ID = 2           |          Length = 16          |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |        Template ID = 263      |         Field Count = 2       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0|   exporterIPv4Address = 8   |        Field Length = 4       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0|   ingressInterface = 10     |        Field Length = 4       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       Figure 24: PSAMP SSRI, Template Record for interface
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |          Set ID = 2           |          Length = 16          |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |        Template ID = 264      |         Field Count = 2       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0|   exporterIPv4Address = 8   |         Field Length = 4      |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0|      lineCardId = 141       |         Field Length = 4      |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        Figure 25: PSAMP SSRI, Template Record for linecard
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |          Set ID = 2           |          Length = 20          |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |        Template ID = 265      |         Field Count = 3       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0|   exporterIPv4Address = 8   |       Field Length = 4        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0|      lineCardId = 141       |        Field Length = 4       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |0|    ingressInterface = 10    |        Field Length = 4       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 Figure 26: PSAMP SSRI, Template Record for linecard and interface

Claise, et al. Standards Track [Page 49] RFC 6313 Export of Structured Data in IPFIX July 2011

 The PSAMP SSRI Data Set is represented as follows:
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |          Set ID = 262         |           Length = 68         |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                    selectionSequenceId = 7                    |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      255      | Observation Point List Len=49 |semantic=allOf |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |     OP1 Template ID = 263     |        OP1 Length = 12        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |         Router 1 exporterIPv4Address = 192.0.2.11             |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                  OP1 ingressInterface = 1                     |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |   OP2&OP3 Template ID = 264   |    OP2 & OP3 Length = 20      |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |         Router 2 exporterIPv4Address = 192.0.2.12             |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                      OP2 lineCardId = A                       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |         Router 3 exporterIPv4Address = 192.0.2.13             |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                      OP3 lineCardId = B                       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |     OP4 Template ID = 265     |         OP4 Length = 16       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |         Router 4 exporterIPv4Address = 192.0.2.14             |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                      OP4 lineCardId = C                       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                   OP4 ingressInterface = 2                    |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                         selectorId = 5                        |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                         selectorId = 10                       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 Figure 27: Example of a PSAMP SSRI Data Record, Encoded Using a
                       subTemplateMultiList
 Note that the Data Record above contains multiple instances of
 Template 264 to represent Observation Point 2 (Router2, linecard A)
 and Observation Point 3 (Router3, linecard B).  Instead, if a single
 Observation Point had both linecard A and linecard B, a basicList
 would be used to represent the list of linecards.

Claise, et al. Standards Track [Page 50] RFC 6313 Export of Structured Data in IPFIX July 2011

10. Relationship with the Other IPFIX Documents

10.1. Relationship with Reducing Redundancy

 "Reducing Redundancy in IP Flow Information Export (IPFIX) and Packet
 Sampling (PSAMP) Reports" [RFC5473] describes a bandwidth saving
 method for exporting Flow or packet information using the IP Flow
 Information Export (IPFIX) protocol.
 It defines the commonPropertiesID Information Element for exporting
 Common Properties.

10.1.1. Encoding Structured Data Element Using Common Properties

 When Structured Data Information Elements contain repeated elements,
 these elements may be replaced with a commonPropertiesID Information
 Element as specified in [RFC5473].  The replaced elements may include
 the basicList, subTemplateList, and subTemplateMultiList Information
 Elements.
 This technique might help reducing the bandwidth requirements for the
 export.  However, a detailed analysis of the gain has not been done;
 refer to Section 8.3 of [RFC5473] for further considerations.

10.1.2. Encoding Common Properties Elements with Structured Data

      Information Element
 Structured Data Information Element MAY be used to define a list of
 commonPropertiesID, as a replacement for the specifications in
 [RFC5473].
 Indeed, the example in Figures 1 and 2 of [RFC5473] can be encoded
 with the specifications in this document.
 +----------------+-------------+---------------------------+
 | sourceAddressA | sourcePortA |     <Flow1 information>   |
 +----------------+-------------+---------------------------+
 | sourceAddressA | sourcePortA |     <Flow2 information>   |
 +----------------+-------------+---------------------------+
 | sourceAddressA | sourcePortA |     <Flow3 information>   |
 +----------------+-------------+---------------------------+
 | sourceAddressA | sourcePortA |     <Flow4 information>   |
 +----------------+-------------+---------------------------+
 |      ...       |     ...     |            ...            |
 +----------------+-------------+---------------------------+
 Figure 28: Common and Specific Properties Exported Together
                            [RFC5473]

Claise, et al. Standards Track [Page 51] RFC 6313 Export of Structured Data in IPFIX July 2011

 +------------------------+-----------------+-------------+
 | index for properties A | sourceAddressA  | sourcePortA |
 +------------------------+-----------------+-------------+
 |          ...           |      ...        |     ...     |
 +------------------------+-----------------+-------------+
 +------------------------+---------------------------+
 | index for properties A |     <Flow1 information>   |
 +------------------------+---------------------------+
 | index for properties A |     <Flow2 information>   |
 +------------------------+---------------------------+
 | index for properties A |     <Flow3 information>   |
 +------------------------+---------------------------+
 | index for properties A |     <Flow4 information>   |
 +------------------------+---------------------------+
 Figure 29: Common and Specific Properties Exported Separately
                   According to [RFC5473]
 +----------------+-------------+---------------------------+
 | sourceAddressA | sourcePortA |     <Flow1 information>   |
 +----------------+-------------+---------------------------+
                                |     <Flow2 information>   |
                                +---------------------------+
                                |     <Flow3 information>   |
                                +---------------------------+
                                |     <Flow4 information>   |
                                +---------------------------+
                                |            ...            |
                                +---------------------------+
  Figure 30: Common and Specific Properties Exported with
               Structured Data Information Element
 The example in Figure 28 could be encoded with a basicList if the
 <Flow information> represents a single Information Element, with a
 subTemplateList if the <Flow information> represents a Template
 Record, or with a subTemplateMultiList if the <Flow information> is
 composed of different Template Records.
 Using Structured Data Information Elements as a replacement for the
 techniques specified in "Reducing Redundancy in IP Flow Information
 Export (IPFIX) and Packet Sampling (PSAMP) Reports" [RFC5473] offers
 the advantage that a single Template Record is defined.  Hence, the
 Collector's job is simplified in terms of Template management and
 combining Template/Options Template Records.

Claise, et al. Standards Track [Page 52] RFC 6313 Export of Structured Data in IPFIX July 2011

 However, it must be noted that using Structured Data Information
 Elements as a replacement for the techniques specified in "Reducing
 Redundancy in IP Flow Information Export (IPFIX) and Packet Sampling
 (PSAMP) Reports" only applies to simplified cases.  For example, the
 "Multiple Data Reduction" (Section 7.1 [RFC5473]) might be too
 complex to encode with Structured Data Information Elements.

10.2. Relationship with Guidelines for IPFIX Testing

 [RFC5471] presents a list of tests for implementers of IP Flow
 Information Export (IPFIX) compliant Exporting Processes and
 Collecting Processes.
 Although [RFC5471] doesn't define any structured data element
 specific tests, the Structured Data Information Elements can be used
 in many of the [RFC5471] tests.
 The [RFC5471] series of test could be useful because the document
 specifies that every Information Element type should be tested.
 However, not all cases from this document are tested in [RFC5471].
 The following sections are especially noteworthy:
    3.2.1.  Transmission of Template with Fixed-Size Information
            Elements
  1. each data type should be used in at least one test. The new

data types specified in Section 4.1 should be included in

         this test.
    3.2.2.  Transmission of Template with Variable-Length Information
            Elements
  1. this test should be expanded to include Data Records

containing variable length basicList, subTemplateList, and

         subTemplateMultiList Information Elements.
    3.3.1.  Enterprise-Specific Information Elements
  1. this test should include the export of basicList,

subTemplateList, and subTemplateMultiList Information

         Elements containing Enterprise-specific Information Elements,
         e.g., see the example in Figure 2.

Claise, et al. Standards Track [Page 53] RFC 6313 Export of Structured Data in IPFIX July 2011

    3.3.3.  Multiple Instances of the Same Information Element in One
            Template
  1. this test should verify that multiple instances of the

basicList, subTemplateList, and subTemplateMultiList

         Information Elements are accepted.
    3.5.  Stress/Load Tests
  1. since the structured data types defined here allow modeling

of complex data structures, they may be useful for stress

         testing both Exporting Processes and Collecting Processes.

10.3. Relationship with IPFIX Mediation Function

 The Structured Data Information Elements would be beneficial for the
 export of aggregated Data Records in mediation function, as was
 demonstrated with the example of the aggregated Observation Point in
 Section 5.3.

11. IANA Considerations

 This document specifies several new IPFIX abstract data types, a new
 IPFIX Data Type Semantic, and several new Information Elements.
 Two new IPFIX registries have been created, and the existing IPFIX
 Information Element registry has been updated as detailed below.

11.1. New Abstract Data Types

 Section 4.1 of this document specifies several new IPFIX abstract
 data types.  Per Section 6 of the IPFIX information model [RFC5102],
 new abstract data types can be added to the IPFIX information model
 in the IPFIX Information Element Data Types registry.
 Abstract data types that have been added to the IPFIX Information
 Element Data Types registry are listed below.

11.1.1. basicList

 The type "basicList" represents a list of any Information Element
 used for single-valued data types.

11.1.2. subTemplateList

 The type "subTemplateList" represents a list of a structured data
 type, where the data type of each list element is the same and
 corresponds with a single Template Record.

Claise, et al. Standards Track [Page 54] RFC 6313 Export of Structured Data in IPFIX July 2011

11.1.3. subTemplateMultiList

 The type "subTemplateMultiList" represents a list of structured data
 types, where the data types of the list elements can be different and
 correspond with different Template definitions.

11.2. New Data Type Semantics

 Section 4.2 of this document specifies a new IPFIX Data Type
 Semantic.  Per Section 3.2 of the IPFIX information model [RFC5102],
 new data type semantics can be added to the IPFIX information model.
 Therefore, the IANA IPFIX informationElementSemantics registry
 [IANA-IPFIX], which contains all the data type semantics from Section
 3.2 of [RFC5102], has been augmented with the "list" value below.

11.2.1. list

 A list is a structured data type, being composed of a sequence of
 elements, e.g., Information Element, Template Record.

11.3. New Information Elements

 Section 4.3 of this document specifies several new Information
 Elements that have been created in the IPFIX Information Element
 registry [IANA-IPFIX].
 New Information Elements that have been added to the IPFIX
 Information Element registry are listed below.

11.3.1. basicList

 Name: basicList
 Description:
 Specifies a generic Information Element with a basicList abstract
 data type.  Examples include a list of port numbers, and a list of
 interface indexes.
 Abstract Data Type: basicList
 Data Type Semantics: list
 ElementId: 291
 Status: current

Claise, et al. Standards Track [Page 55] RFC 6313 Export of Structured Data in IPFIX July 2011

11.3.2. subTemplateList

 Name: subTemplateList
 Description:
 Specifies a generic Information Element with a subTemplateList
 abstract data type.
 Abstract Data Type: subTemplateList
 Data Type Semantics: list
 ElementId: 292
 Status: current

11.3.3. subTemplateMultiList

 Name: subTemplateMultiList
 Description:
 Specifies a generic Information Element with a
 subTemplateMultiList abstract data type.
 Abstract Data Type: subTemplateMultiList
 Data Type Semantics: list
 ElementId: 293
 Status: current

11.4. New Structured Data Semantics

 Section 4.4 of this document specifies a series of new IPFIX
 structured data type semantics, which is expressed as an 8-bit value.
 This requires the creation of a new "IPFIX Structured Data Types
 Semantics" IPFIX subregistry [IANA-IPFIX].
 Entries may be added to this subregistry subject to a Standards
 Action [RFC5226].  Initially, this registry includes all the
 structured data type semantics listed below.

11.4.1. undefined

 Name: undefined
 Description: The "undefined" structured data type semantic specifies
 that the semantic of list elements is not specified and that, if a
 semantic exists, then it is up to the Collecting Process to draw its
 own conclusions.  The "undefined" structured data type semantic is
 the default structured data type semantic.
 Value: 0xFF
 Reference: RFC 6313

Claise, et al. Standards Track [Page 56] RFC 6313 Export of Structured Data in IPFIX July 2011

11.4.2. noneOf

 Name: noneOf
 Description: The "noneOf" structured data type semantic specifies
 that none of the elements are actual properties of the Data Record.
 Value: 0x00
 Reference: RFC 6313

11.4.3. exactlyOneOf

 Name: exactlyOneOf
 Description: The "exactlyOneOf" structured data type semantic
 specifies that only a single element from the structured data is an
 actual property of the Data Record.  This is equivalent to a logical
 XOR operation.
 Value: 0x01
 Reference: RFC 6313

11.4.4. oneOrMoreOf

 Name: oneOrMoreOf
 Description: The "oneOrMoreOf" structured data type semantic
 specifies that one or more elements from the list in the structured
 data are actual properties of the Data Record.  This is equivalent to
 a logical OR operation.
 Value: 0x02
 Reference: RFC 6313

11.4.5. allOf

 Name: allOf
 Description: The "allOf" structured data type semantic specifies that
 all of the list elements from the structured data are actual
 properties of the Data Record.
 Value: 0x03
 Reference: RFC 6313

Claise, et al. Standards Track [Page 57] RFC 6313 Export of Structured Data in IPFIX July 2011

11.4.6. ordered

 Name: ordered Description: The "ordered" structured data type
 semantic specifies that elements from the list in the structured data
 are ordered.
 Value: 0x04
 Reference: RFC 6313

12. Security Considerations

 The addition of complex data types necessarily complicates the
 implementation of the Collector.  This could easily result in new
 security vulnerabilities (e.g., buffer overflows); this creates
 additional risk in cases where either Datagram Transport Layer
 Security (DTLS) is not used or if the Observation Point and Collector
 belong to different trust domains.  Otherwise, the same security
 considerations as for the IPFIX protocol [RFC5101] and the IPFIX
 information model [RFC5102] apply.

13. References

13.1. Normative References

 [RFC2119]    Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.
 [RFC5101]    Claise, B., Ed., "Specification of the IP Flow
              Information Export (IPFIX) Protocol for the Exchange of
              IP Traffic Flow Information", RFC 5101, January 2008.
 [RFC5102]    Quittek, J., Bryant, S., Claise, B., Aitken, P., and J.
              Meyer, "Information Model for IP Flow Information
              Export", RFC 5102, January 2008.
 [RFC5226]    Narten, T. and H. Alvestrand, "Guidelines for Writing an
              IANA Considerations Section in RFCs", BCP 26, RFC 5226,
              May 2008.

13.2. Informative References

 [RFC3917]    Quittek, J., Zseby, T., Claise, B., and S. Zander,
              "Requirements for IP Flow Information Export (IPFIX)",
              RFC 3917, October 2004.

Claise, et al. Standards Track [Page 58] RFC 6313 Export of Structured Data in IPFIX July 2011

 [RFC5103]    Trammell, B. and E. Boschi, "Bidirectional Flow Export
              Using IP Flow Information Export (IPFIX)", RFC 5103,
              January 2008.
 [RFC5470]    Sadasivan, G., Brownlee, N., Claise, B., and J. Quittek,
              "Architecture for IP Flow Information Export", RFC 5470,
              March 2009.
 [RFC5471]    Schmoll, C., Aitken, P., and B. Claise, "Guidelines for
              IP Flow Information Export (IPFIX) Testing", RFC 5471,
              March 2009.
 [RFC5472]    Zseby, T., Boschi, E., Brownlee, N., and B. Claise, "IP
              Flow Information Export (IPFIX) Applicability", RFC
              5472, March 2009.
 [RFC5473]    Boschi, E., Mark, L., and B. Claise, "Reducing
              Redundancy in IP Flow Information Export (IPFIX) and
              Packet Sampling (PSAMP) Reports", RFC 5473, March 2009.
 [RFC5475]    Zseby, T., Molina, M., Duffield, N., Niccolini, S., and
              F. Raspall, "Sampling and Filtering Techniques for IP
              Packet Selection", RFC 5475, March 2009.
 [RFC5476]    Claise, B., Ed., Johnson, A., and J. Quittek, "Packet
              Sampling (PSAMP) Protocol Specifications", RFC 5476,
              March 2009.
 [RFC5477]    Dietz, T., Claise, B., Aitken, P., Dressler, F., and G.
              Carle, "Information Model for Packet Sampling Exports",
              RFC 5477, March 2009.
 [IANA-IPFIX] IANA, "IP Flow Information Export (IPFIX) Entities",
              <http://www.iana.org/>.

14. Acknowledgements

 The authors would like to thank Zhipu Jin, Nagaraj Varadharajan,
 Brian Trammel, Atsushi Kobayashi, and Rahul Patel for their feedback,
 and Gerhard Muenz, for proofreading the document.

Claise, et al. Standards Track [Page 59] RFC 6313 Export of Structured Data in IPFIX July 2011

Appendix A. Additions to XML Specification of IPFIX Information

           Elements and Abstract Data Types
 This appendix contains additions to the machine-readable description
 of the IPFIX information model coded in XML in Appendices A and B in
 [RFC5102].  Note that this appendix is of informational nature, while
 the text in Section 4 (generated from this appendix) is normative.
 The following field definitions are appended to the IPFIX information
 model in Appendix A of [RFC5102].
 <field name="basicList"
         dataType="basicList"
         group="structured-data"
         dataTypeSemantics="List"
         elementId="291" applicability="all" status="current">
    <description>
      <paragraph>
         Represents a list of zero or more instances of
         any Information Element, primarily used for
         single-valued data types.  Examples include a list of port
         numbers, list of interface indexes, and a list of AS in a
         BGP AS-PATH.
      </paragraph>
    </description>
  </field>
  <field name="subTemplateList"
         dataType="subTemplateList"
         group="structured-data"
         dataTypeSemantics="List"
         elementId="292" applicability="all" status="current">
    <description>
      <paragraph>
         Represents a list of zero or more instances of a
         structured data type, where the data type of each list
         element is the same and corresponds with a single
         Template Record.  Examples include a structured data type
         composed of multiple pairs of ("MPLS label stack entry
         position", "MPLS label stack value"), a structured data
         type composed of performance metrics, and a structured data
         type composed of multiple pairs of IP address.
      </paragraph>
    </description>
  </field>

Claise, et al. Standards Track [Page 60] RFC 6313 Export of Structured Data in IPFIX July 2011

  <field name="subTemplateMultiList"
         dataType="subTemplateMultiList"
         group="structured-data"
         dataTypeSemantics="List"
         elementId="293" applicability="all" status="current">
    <description>
      <paragraph>
        Represents a list of zero or more instances of
        structured data types, where the data type of each list
        element can be different and corresponds with
        different Template definitions.  Examples include, a
        structured data type composed of multiple access-list
        entries, where entries can be composed of different
        criteria types.
      </paragraph>
    </description>
  </field>
 The following structured data type semantic definitions are appended
 to the IPFIX information model in Appendix A of [RFC5102].
 <structuredDataTypeSemantics>
   <structuredDataTypeSemantic name="undefined" value="255">
     <description>
       <paragraph>
        The "undefined" structured data type semantic specifies
        that the semantic of list elements is not specified and
        that, if a semantic exists, then it is up to the
        Collecting Process to draw its own conclusions.  The
        "undefined" structured data type semantic is the default
        structured data type semantic.
       </paragraph>
     </description>
   </structuredDataTypeSemantic>
   <structuredDataTypeSemantic name="noneOf" value="0">
     <description>
       <paragraph>
        The "noneOf" structured data type semantic specifies
        that none of the elements are actual properties of the
        Data Record.
       </paragraph>
     </description>
   </structuredDataTypeSemantic>

Claise, et al. Standards Track [Page 61] RFC 6313 Export of Structured Data in IPFIX July 2011

   <structuredDataTypeSemantic name="exactlyOneOf" value="1">
     <description>
       <paragraph>
        The "exactlyOneOf" structured data type semantic
        specifies that only a single element from the structured
        data is an actual property of the Data Record.  This is
        equivalent to a logical XOR operation.
       </paragraph>
     </description>
   </structuredDataTypeSemantic>
   <structuredDataTypeSemantic name="oneOrMoreOf" value="2">
     <description>
       <paragraph>
        The "oneOrMoreOf" structured data type semantic
        specifies that one or more elements from the list in the
        structured data are actual properties of the Data
        Record.  This is equivalent to a logical OR operation.
       </paragraph>
     </description>
   </structuredDataTypeSemantic>
   <structuredDataTypeSemantic name="allOf" value="3">
     <description>
       <paragraph>
        The "allOf" structured data type semantic specifies that
        all of the list elements from the structured data are
        actual properties of the Data Record.
       </paragraph>
     </description>
   </structuredDataTypeSemantic>
   <structuredDataTypeSemantic name="ordered" value="4">
     <description>
       <paragraph>
        The "ordered" structured data type semantic specifies
        that elements from the list in the structured data are
        ordered.
       </paragraph>
     </description>
   </structuredDataTypeSemantic>
 </structuredDataTypeSemantics>
 The following schema definitions are appended to the abstract data
 types defined in Appendix B of [RFC5102].  This schema and its
 namespace are registered by IANA at
 http://www.iana.org/assignments/xml-registry/schema/ipfix.xsd.

Claise, et al. Standards Track [Page 62] RFC 6313 Export of Structured Data in IPFIX July 2011

<simpleType name="dataType">

 <restriction base="string">
   <enumeration value="basicList">
     <annotation>
       <documentation>
         Represents a list of zero or more instances of
         any Information Element, primarily used for
         single-valued data types.  Examples include a list of port
         numbers, a list of interface indexes, and a list of AS in a
         BGP AS-PATH.
       </documentation>
     </annotation>
   </enumeration>
   <enumeration value="subTemplateList">
     <annotation>
       <documentation>
         Represents a list of zero or more instances of a
         structured data type, where the data type of each list
         element is the same and corresponds with a single
         Template Record.  Examples include a structured data type
         composed of multiple pairs of ("MPLS label stack entry
         position", "MPLS label stack value"), a structured
         data type composed of performance metrics, and a
         structured data type composed of multiple pairs of IP
         address.
       </documentation>
     </annotation>
   </enumeration>
   <enumeration value="subTemplateMultiList">
     <annotation>
       <documentation>
         Represents a list of zero or more instances of
         structured data types, where the data type of each
         list element can be different and corresponds with
         different Template definitions.  An example is a
         structured data type composed of multiple
         access-list entries, where entries can be
         composed of different criteria types.
       </documentation>
     </annotation>
   </enumeration>
 </restriction>

</simpleType>

Claise, et al. Standards Track [Page 63] RFC 6313 Export of Structured Data in IPFIX July 2011

<simpleType name="dataTypeSemantics">

 <restriction base="string">
   <enumeration value="List">
     <annotation>
       <documentation>
         Represents an arbitrary-length sequence of structured
         data elements, either composed of regular Information
         Elements or composed of data conforming to a Template
         Record.
       </documentation>
     </annotation>
   </enumeration>
 </restriction>

</simpleType>

<complexType name="structuredDataTypeSemantics">

 <sequence>
   <element name="structuredDataTypeSemantic"
            minOccurs="1" maxOccurs="unbounded">
     <complexType>
       <sequence>
         <element name="description" type="text"/>
       </sequence>
       <attribute name="name" type="string" use="required"/>
       <attribute name="value" type="unsignedByte" use="required"/>
     </complexType>
   </element>
 </sequence>

</complexType>

<element name="structuredDataTypeSemantics"

        type="structuredDataTypeSemantics">
 <annotation>
   <documentation>
     Structured data type semantics express the relationship
     among multiple list elements in a structured data
     Information Element.
   </documentation>
 </annotation>

</element>

Claise, et al. Standards Track [Page 64] RFC 6313 Export of Structured Data in IPFIX July 2011

Appendix B. Encoding IPS Alert Using Structured Data Information

           Elements
 In this section, an IPS alert example is used to demonstrate how
 complex data and multiple levels of hierarchy can be encoded using
 Structured Data Information Elements.  Also, this example
 demonstrates how a basicList of subTemplateLists can be used to
 represent semantics at multiple levels in the hierarchy.
 An IPS alert consists of the following mandatory attributes:
 signatureId, protocolIdentifier, and riskRating.  It can also contain
 zero or more participants, and each participant can contain zero or
 more attackers and zero or more targets.  An attacker contains the
 attributes sourceIPv4Address and applicationId, and a target contains
 the attributes destinationIPv4Address and applicationId.
 Note that the signatureId and riskRating Information Element fields
 are created for these examples only; the Field IDs are shown as N/A.
 The signatureId helps to uniquely identify the IPS signature that
 triggered the alert.  The riskRating identifies the potential risk,
 on a scale of 0-100 (100 being most serious), of the traffic that
 triggered the alert.
 Consider the example described in case study 2 of Section 5.6. The
 IPS alert contains participants encoded as a subTemplateList with
 semantic allOf.  Each participant uses a basicList of
 subTemplateLists to represent attackers and targets.  For the sake of
 simplicity, the alert has two participants P1 and P2.  In participant
 P1, attacker A1 or A2 attacks target T1.  In participant P2, attacker
 A3 attacks targets T2 and T3.

Claise, et al. Standards Track [Page 65] RFC 6313 Export of Structured Data in IPFIX July 2011

 Participant P1:
      (basicList, allOf,
            (subTemplateList, exactlyOneOf, attacker A1, A2)
            (subTemplateList, undefined, target T1)
      )
 Participant P2:
      (basicList, allOf,
            (subTemplateList, undefined, attacker A3,
            (subTemplateList, allOf, targets T2, T3)
      )
 Alert :
         (subTemplateList, allOf, Participant P1, Participant P2)
  1. —————————————————————–

| | | participant

  sigId |protocol| risk   |      attacker   |      target
        |   Id   | Rating |    IP   | appId |    IP      | appId
  ------------------------------------------------------------------
  1003     17      10      192.0.2.3  103    192.0.2.103    3001
                           192.0.2.4  104
                           192.0.2.5  105    192.0.2.104    4001
                                             192.0.2.105    5001
  ------------------------------------------------------------------
  Participant P1 contains:
  Attacker A1: (IP, appId)=(192.0.2.3, 103)
  Attacker A2: (IP, appId)=(192.0.2.4, 104)
  Target T1: (IP, appId)= (192.0.2.103, 3001)
  Participant P2 contains:
  Attacker A3: (IP, appId) = (192.0.2.5, 105)
  Target T2: (IP, appId)= (192.0.2.104, 4001)
  Target T3: (IP, appId)= (192.0.2.105, 5001)
  To represent an alert, the following Templates are defined:
  Template for target (268)
  Template for attacker (269)

Claise, et al. Standards Track [Page 66] RFC 6313 Export of Structured Data in IPFIX July 2011

  Template for participant (270)
  Template for alert (271)
       alert (271)
       |  (signatureId)
       |  (protocolIdentifier)
       |  (riskRating)
       |
       +------- participant (270)
                |
                +------- attacker (269)
                |           (sourceIPv4Address)
                |           (applicationId)
                |
                +------- target (268)
                         |  (destinationIPv4Address)
                         |  (applicationId)
 Note that the attackers are always composed of a single
 applicationId, while the targets typically have multiple
 applicationIds; for the sake of simplicity, this example shows only
 one applicationId in the target.
 Template Record for target, with the Template ID 268:
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |        Set ID = 2             |      Length = 16 octets       |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |       Template ID = 268       |       Field Count = 2         |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |0| destinationIPv4Address = 12 |       Field Length = 4        |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |0|       applicationId = 95    |       Field Length = 4        |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
           Figure 31: Encoding IPS Alert, Template for Target

Claise, et al. Standards Track [Page 67] RFC 6313 Export of Structured Data in IPFIX July 2011

  Template Record for attacker, with the Template ID 269:
   0                   1                   2                   3
   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |         Set ID = 2            |      Length = 16 octets       |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |       Template ID = 269       |       Field Count = 2         |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |0|    sourceIPv4Address = 8    |       Field Length = 4        |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |0|     applicationId = 95      |       Field Length = 4        |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          Figure 32: Encoding IPS Alert, Template for Attacker
  Template Record for participant, with the Template ID 270:
   0                   1                   2                   3
   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |         Set ID = 2            |      Length = 12 octets       |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |       Template ID = 270       |       Field Count = 1         |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |0|       basicList = 291       |     Field Length = 0xFFFF     |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        Figure 33: Encoding IPS Alert, Template for Participant
 The Template Record for the participant has one basicList Information
 Element, which is a list of subTemplateLists of attackers and
 targets.

Claise, et al. Standards Track [Page 68] RFC 6313 Export of Structured Data in IPFIX July 2011

 Template Record for IPS alert, with the Template ID 271:
   0                   1                   2                   3
   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |         Set ID = 2            |      Length = 24 octets       |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |       Template ID = 271       |       Field Count = 4         |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |0|    signatureId = N/A        |       Field Length = 2        |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |0|   protocolIdentifier = 4    |       Field Length = 1        |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |0|     riskRating = N/A        |       Field Length = 1        |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |0|     subTemplateList = 292   |     Field Length = 0xFFFF     |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
         Figure 34: Encoding IPS Alert, Template for IPS Alert
 The subTemplateList in the alert Template Record contains a list of
 participants.
 The Length of basicList and subTemplateList are encoded in three
 bytes even though they may be less than 255 octets.
 The Data Set is represented as follows:
   0                   1                   2                   3
   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |          Set ID = 271         |         Length = 102          |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |      signatureId = 1003       | protocolId=17 | riskRating=10 |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |      255      |participant List Length  = 91  |semantic=allOf |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  | participant Template ID = 270 |     255       | P1 List Len = |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |      41       | semantic=allOf|    P1 List Field ID = 292     |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  | P1 List Field ID Len = 0xFFFF |      255      |P1 attacker ...|
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  | List Len = 19 |sem=exactlyOne | P1 attacker Template ID = 269 |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |          P1 attacker A1 sourceIPv4Address = 192.0.2.3         |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |               P1 attacker A1 applicationId = 103              |

Claise, et al. Standards Track [Page 69] RFC 6313 Export of Structured Data in IPFIX July 2011

  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |          P1 attacker A2 sourceIPv4Address = 192.0.2.4         |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |               P1 attacker A2 applicationId = 104              |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |      255      | P1 target List Len = 11       | sem=undefined |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |  P1 target Template ID = 268  | P1 target T1 destinationIPv4  |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  | ... Address = 192.0.2.103     |P1 target T1 applicationId =...|
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  | ...       3001                |      255      | P2 List Len = |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  | ...  41       | semantic=allOf|    P2 List Field ID = 292     |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  | P2 List Field ID Len = 0xFFFF |      255      |P2 attacker ...|
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  | List Len = 11 | sem=undefined | P2 attacker Template ID = 269 |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |          P2 attacker A3 sourceIPv4Address = 192.0.2.5         |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |               P2 attacker A3 applicationId = 105              |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |      255      |    P2 target List Len = 19    |semantic=allOf |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |  P2 target Template ID = 268  | P2 target T2 destinationIPv4  |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  | ... Address = 192.0.2.104     |P2 target T2 applicationId =...|
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  | ...       4001                | P2 target T3 destinationIPv4  |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  | ... Address = 192.0.2.105     |P2 target T3 applicationId =...|
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  | ...       5001                |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        Note: sem=exactlyOne represents semantic=exactlyOneOf
                Figure 35: Encoding IPS Alert, Data Set

Claise, et al. Standards Track [Page 70] RFC 6313 Export of Structured Data in IPFIX July 2011

Authors' Addresses

 Benoit Claise
 Cisco Systems, Inc.
 De Kleetlaan 6a b1
 Diegem 1813
 Belgium
 Phone: +32 2 704 5622
 EMail: bclaise@cisco.com
 Gowri Dhandapani
 Cisco Systems, Inc.
 13615 Dulles Technology Drive
 Herndon, Virginia 20171
 United States
 Phone: +1 408 853 0480
 EMail: gowri@cisco.com
 Paul Aitken
 Cisco Systems, Inc.
 96 Commercial Quay
 Commercial Street
 Edinburgh, EH6 6LX
 United Kingdom
 Phone: +44 131 561 3616
 EMail: paitken@cisco.com
 Stan Yates
 Cisco Systems, Inc.
 7100-8 Kit Creek Road
 PO Box 14987
 Research Triangle Park, North Carolina 27709-4987
 United States
 Phone: +1 919 392 8044
 EMail: syates@cisco.com

Claise, et al. Standards Track [Page 71]

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